Elements of the Golf Swing

SECOND EDITION

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www.JACOBS3D.com

FOREWORD AND CONTRIBUTIONS FROM DR. STEVEN NESBIT

Copyright © 2020 by Michael Jacobs All Rights Reserved. This book or any portion thereof may not be reproduced or used in any manner whatsoever without the express written permission of the publisher, except for the use of brief quotations in a review.

Printed in the United States of America First Printing, 2016 Second Edition, 2021 ISBN 9798714463303 Independently Published RSB Golf Inc. 105 Clancy Road Manorville, NY 11949 www.jacobs3D.com Second Edition designed by Keri Ello Reiter

DEDICATION

THIS BOOK IS DEDICATED TO DR. STEVEN NESBIT For his belief in my hard work and relentless desire to design a swing analysis system that connects his scientific discoveries to the world of golf. For the past nine years, we have put the mechanical meaning of the golf swing under a microscope, and his patience and open-mindedness have allowed me to take a journey that no other golf professional has been on before.

FOREWORD

Dr. Steven Nesbit

Right now, a golf instructor could spend around $100,000 and within a few weeks have a studio filled with motion capture and force measurement equipment that would have been the envy of any university mechanical engineering department in the country just a few years ago.

That’s truly an amazing development.

Go back a little farther, to 1991, and information on what a golfer and the club really does during the swing—and the equipment to measure it—just didn’t exist.

The USGA meant to change that, and they came to Lafayette College for some help with a project to draw computer models for golf clubs.

They wanted to find out exactly what clubs contributed to distance—the first step in coming up with distance parameters in the game.

I was relatively new to Lafayette at the time,and it was a project that the rest of the department didn’t think was that exciting. So it fell to me to meet with Frank Thomas of the USGA and come up with a solution. It was a subject that aligned very well with my expertise, in robotics, and one that I had a scientist’s interest in. The concept of biomechanics in golf was out there, but there hadn’t been much beyond the basics published about it—clubhead speed, how long impact

lasted. I could see there was room for some interesting research.

Right before I made the trip to Far Hills, N.J. for the meeting with Frank, I saw a presentation from a friend of mine in the software business on a brand new motion capture system designed to analyze human motion. The concept of three-dimensional dynamics was fascinating to me, and it gave me an idea.

When Frank and I met, I told him we could measure what happened with the club, but the technology now existed to biomechanically model the entire golfer—club included. We could figure out what was happening inside the swing in terms of motion, force and torque.

Frank was one of the most open-minded scientists I had ever met. I was asking him to undertake a much more ambitious—and expensive—project than he had planned, on something that had never been tried before. By the time the meeting was over, we had a plan.

Over the next several years, I used my background in robotics to devise what would become the USGA’s digital swing model—a comprehensive study of the three-dimensional dynamics of the body and club. We developed a database of kinetic and kinematic parameters, and Frank and the USGA were able to use that information in support of a new generation of equipment rules.

The USGA research turned into my first two published papers on the golf swing, and I was able to get a grant at Lafayette to build my own motion analysis system. From there, I could study not only the golf swing, but also the movements from other sports like softball and tennis.

What the motion analysis system and research has allowed us to do is look beyond what movements a person is making and study what actually makes them move. The golf swing is obviously very complicated—just like a serve is in tennis—but the method of analysis isn’t complicated. It is the fundamentals of mechanics, applied to the motion within the sport.

When I started this research, I came in without any background in golf as a player or an instruc-

FOREWORD

tor. I had some sentimentality about the sport because it was important to my father, but I didn’t have any prejudice about what should happen, or a preconceived notion about what to expect. When I handed Frank Thomas the original results at the USGA and explained to him that the hub path— the route the nexus between the hands and handle of the club takes during the swing—wasn’t circular, he was ready to string me up. It went against what everybody had assumed about the golf swing for years—that the path was circular enough to call the radius pretty much constant throughout. I was just reporting what the physics told me. The information I collected and the research I did wasn’t any secret. It was out there for anybody to see and build upon. But Michael Jacobs and Brian Manzella were the first ones to come up to Lafayette to really try to understand it from the golf instructor’s perspective.

Mike came into my office the first time with a notebook overflowing with printouts of all my articles. They were outlined, highlighted and full of questions. It was amazing, the level of study he had done. And from the questions he asked, it was clear he was deeply interested in not just the practical application of the information, but the quantitative side—what do the numbers mean, and how do you get to them?

And on the other side of the equation, it was fascinating to learn from Mike the context of the kinematic fundamentals I had been researching.

Looking at the data, I could make an observation that torque was really increasing at a certain point in the motion, and Mike could tie it into what was physically happening in the swing and how it was meaningful. I was excited to work on this project with Mike because so many people both inside and outside academia think that research papers get published and just sit on a shelf somewhere. This was an opportunity to show through Mike’s 3D software that the information we had been collecting and organizing had a practical application for golf instruction.

And that’s what The Elements of the Swing (and Jacobs 3D) does. It gives any player or teacher the true “what” and “why” of the movement of the club in the swing.

One of the first questions I get about kinetics

and kinematics related to a specific sport is about what the “optimum” motion is. Everybody wants to know how to do it perfectly.

The answer might not be satisfying for a player or teacher, but it’s turned out to be a fascinating one for those of us interested in the science. The kinematics, kinetics and mechanics tell us that there isn’t one thing or one answer to it all.

It’s complex, and the “answer” is many things, wrapped up together.

Why is it that some small people with less obvious muscle power can produce more club- head speed than some large, strong people? It’s about energy, and how much energy you can put into the club with your body.

The average person can produce more than enough energy to hit the ball a long way. But the people who hit it far are able to transfer more of that energy into the ball.

They do it more efficiently, and more effectively.

That’s part of what makes the Elements of the Swing—and Mike’s project in general—so interesting. He’s determined to use the science and research to start answering those how and why questions for every golfer—questions we’ve only been able to guess about before. It’s a fascinating road, and we’re just at the beginning of it. Soon, you’ll be able to look at the output from Mike’s software and see not just what’s happening to the club but what every individual joint and muscle group in the body is doing to contribute.

Mike is right out in front with this—in the hardware it takes to build the best studio, the software to pull the data together and analysis on top of it. He’s driven, and he’s motivated to stay out front—a motivation I wish all my students at Lafayette had. They’re all gifted, but that’s meaningless without the drive and the desire to know more. Mike is never satisfied with what he knows at the moment. To me, that’s one of the highest compliments you can pay somebody in this field, and he unquestionably deserves it.

It’s a pleasure to work on this project, and I hope you enjoy diving into the Elements of the Swing as much I enjoyed helping Mike with its construction.

INTRODUCTION

The Elements of the Swing

For more than 20 years, I’ve been looking for the “truth” behind the golf swing. More than just knowing how the best players move the club, I wanted to know why certain combinations of motions work better than others.

Over the years, golfers have assembled a huge body of knowledge on the swing, and passing pieces of that information from mentor to student has been the main way we learn to play golf.

I think there’s an important place for that mentoring, but it doesn’t mean we should stop there.

We’re in the most exciting era in the history of golf instruction right now. Any full-time teacher with the desire (and funds) to invest some time, energy and resources into his or her craft can assemble a teaching studio more technologically advanced than anyone could have dreamed 20 years ago.

Even if you leave aside technological leaps like the GEARS optical motion capture system, TrackMan and force plates—virtually all of us in the teaching business carry a device in our pockets that can do more than any teacher had at his or her disposal even in 1990. With an iPhone, I can record a student’s swing in regular speed and slow motion, use an app to mark it up and text it to him or her before we’re even done with the lesson. And we’re just scratching the surface of what the phone can do.

But all the technology in the world doesn’t mean anything—and doesn’t help teachers and players get better—if the underlying swing theories behind it aren’t sound or are incomplete.

Those theories need to be facts.

I can use my GEARS optical motion capture

system to measure an amazing array of movements, and see in great detail how or what the right arm or the hips or the clubhead does during Rickie Fowler’s swing and compare it to Joe Hacker’s. GEARS now shows a functional skeleton, so it’s possible to see what individual segments are doing during the swing. Measuring movement is great, but what makes those movements happen?

And what combination of movements is ideal for a given player?

That’s where my software program Jacobs 3D comes in.

KINETICS VS. KINEMATICS Golf technology has gotten very good at measuring the kinematics—or movement—within a swing. We know how far the clubhead travels from address to the top of the backswing and down through impact. We can measure things like “turn” and “sway” and “swing plane.” TrackMan tells you an amazing amount of detailed information about how the club and the ball move. You can clip a small sensor onto your clubs, go play a round and come back with impressively accurate club head speed and distance measurements.

You can think of kinematics as the speed and acceleration of that car going by you on the road in front of your house.

But knowing how fast the car goes and how much it is speeding up (or slowing down) doesn’t tell you anything about what is making the car go.

It doesn’t reveal anything about the engine under the hood.

Kinetics is the study of force—what creates movement. In a golf swing, it’s useful to know what direction and how fast the club is moving.

But what if you could identify the actual forces and torques that produce that movement? You could move back one step in the chain and learn from the source, instead of responding to a reaction several steps down the line.

With Jacobs 3D, we can now identify and measure those forces and torques.

INTRODUCTION

WHAT IS JACOBS 3D? Every iteration of golf technology has pushed the boundaries of what we can measure in the swing. In my studio, I’ve worked my way up from radar to launch monitors, force plates, balance plates, pressure insoles and up to optical motion capture with the GEARS system.

Each of those technological advancements had their merits, and offered a few pieces to the puzzle.

But none of them brought it all together and gave me the answers I was looking for—even after consulting with some of the preeminent minds in the worlds of biomechanics and golf science.

With the help of my good friend Michael Neff at GEARS Golf, I installed an upgraded Research and Development model of the GEARS system in my studio seven years ago. Using the data from that system and Optitracks as a jumping-off point, I started working with Dr. Steven Nesbit at Lafayette College to develop my own swing analysis software.

Dr. Nesbit is the leading expert in bioengineering—the use of engineering principles in human applications—and was the lead scientist on the most comprehensive scientific study of the relationship between the human body and golf swing ever undertaken. Working on the team established

by Frank Thomas at the USGA, Dr. Nesbit patented a system for the three-dimensional analysis of the golf swing that is to this day the industry standard.

After spending years studying Dr. Nesbit’s three-dimensional analysis protocol, I approached him with the concept of Jacobs 3D. With Dr. Nesbit’s expertise in bioengineering and software design, he was able to create the algorithms to crunch the data and piece together a user-friendly software that finally answered the questions I had been posing all those years.

For the first time, we can “look under the hood” of any student and understand not just the what, but the how and why of the swing. And more importantly, we can use that information to optimize a player’s swing more quickly and more thoroughly than ever before.

In basic terms, Jacobs 3D shows the club’s movement through the swing and the forces and torques acting on that movement.

This information lets golfers focus their attention on techniques that actually change the way they force and torque the club. If some- thing a player is doing (or not doing) doesn’t impact those torques or forces in the desired way, that movement (or lack of it) isn’t contributing to the efficiency of the swing.

WHAT DOES IT MEASURE? Phase One of Jacobs 3D measures more than 115 “parameters” during the swing. These range from “standard” measurements you’ve heard before—like alpha, beta and gamma swing torques— to some new fundamentals I believe will become a basic part of golf instruction in the 21st century, like the hub path, center of curvature and the Relative Swing Plane.

In this book, I’ll explain each of the fundamentals and what they mean for the swing, and offer a collection of swing “templates”—with their Jacobs 3D “fingerprint.” Teachers and players will be able to have a common language and understanding of the forces in the swing and what differentiates players of different power and skill levels.

We now have the equivalent of a CT scan for the golf swing.

To give two basic examples, think about what you know about how the club should line up through impact. Conventional teaching—and even biomechanical study—has long said that the centrifugal force of the swing acts on its own to extend the club through impact. Or, consider the movement of the club through transition. Do good players throw the club head immediately from the top? Do they start to “hold” or “create” lag?

How many arguments have you read on the internet about those subjects, where well meaning teachers have used everything from personal experience to video to still photographs to prove or disprove some point?

Now, we have quantifiable data that answers those questions and more.

THE ELEMENTS OF THE SWING

the studios of Ambassadors worldwide.

But even though an ambassador location is the only place you can get your swing captured and then analyzed through Jacobs 3D, the overall concepts revealed through measuring hundreds of As good as technology has gotten over the last swings are too important to hide away and save for 20 years, teachers have still been guessing about a those who make the trip to our studios. lot of the things happening in a swing. And we’ve This manual will cover the basics of the Jabeen guessing about the exact movements and sequences of movements that separate good players cobs 3D Convention—the definitions and paramfrom great players and players who hit it 280 vs. 310. eters used within the software to provide the most With Jacobs 3D, we don’t have to guess anymore. complete dissection of a golf swing available today.

The book will describe these parameters, what they So much of golf instruction is trial and error now—adjusting this knob and seeing what happens, mean and how they work together. It will also dethen tweaking another lever over here. With Jacobs scribe a new way of looking at the age-old concept of “swing plane,” but this time with the full weight 3D—and some basic training on how to interpret of mechanical research behind it. This Relative the fundamentals—teachers will have the ability to see problems and solutions much more quickly, and Swing Plane—the relationship between how the hub path and the clubhead path move—is one of to optimize a player in a fraction of the time.

The practical application of this information to the most exciting new developments in golf instruction since the advent of drawing lines on video. make players better faster is my primary goal with With a basic understanding of what Jacobs 3D Jacobs 3D, but I also have an important secondary measures and how the parameters equate to the motivation in this process. movement of the club, any teacher or player will As the world of teaching evolves and changes gain a new understanding about the true causes with new ideas and new technology, those of us and effects in a golf swing. Not only will you be able interested in learning and teaching at the highto achieve that understanding without owning the est level can get there faster if we can agree on software—you’ll be able to get it with the naked eye a common “teaching language.” If you and I are and a half dozen swings on the range. arguing about the definition of angular and linear And better yet, if you get to the end and find movement in a swing, we’re wasting time we could yourself wanting more, don’t worry. It’s here, The be spending solving the real swing problems our Science of the Golf Swing, with complete descripstudents have. tions of every Jacobs 3D parameter is also available With Jacobs 3D, the hope is that the analysis for teachers and other dedicated swing enthusiasts. that comes from the software will help move us It really is the dawn of a new age in golf intoward a unified conversational convention—that struction. common teaching language. At the top levels of teaching, we should be able to talk about alpha, beta and gamma torques or the hub path the way MICHAEL JACOBS 15-handicappers talk about slices and hooks at the Top 50 Golf Teacher in America Golf Digest 2017 – Present driving range.

WHAT DOES JACOBS 3D MEAN FOR TEACHERS AND PLAYERS?

WHAT DOES THIS MANUAL DO, AND HOW SHOULD YOU USE IT?

Top 100 Golf Teacher in America

Jacobs 3D isn’t conventional software in the sense that you can buy it and run it on your own computer. The software is used exclusively in the teaching studio at Jacobs 3D Headquarters and at

PGA Teacher of the Year

Golf Magazine 2016 – Present

Best Young Golf Teacher in America Golf Digest 2017

Metropolitan Section 2012

PGA Horton Smith Award Metropolitan Section 2020

CHAPTER 1

Forces & Torques

Remember the car analogy we were talking about in the introduction?

There’s a reason why I used it. When you’re watching a NASCAR race, it’s all right in front of you. All the cars start in a pack, and they go around a track over and over again, changing positions, accelerating and slowing down.

Sometimes they crash into each other—or the wall— and at the end, one car goes over the finish line first.

With photography, video and now 3D motion capture, we’ve spent more than 150 years watching golf swings like fans watch a car race on television or in the stands. How do the positions change?

How does one piece look compared to the other?

How fast does everything go?

Let’s go back to the racecar garage and see how they put those cars together and you will get a different understanding of what makes certain teams win races and others stay at the back of the pack.

The drivers are important, but the crews also have an incredible understanding of what goes on under the hood, and what makes that car accelerate, turn and stop.

The terms they use—force and torque—are tremendously important in the world of high performance.

In the simplest terms, a force is a push or a pull that causes that an object to move and a torque is a

twist that causes an object to rotate.

As you’re about to discover, those terms are just as important in golf. With Jacobs 3D, we can now describe golfers and golf swings much like the way NASCAR engineers measure racecar performance.

We can measure kinematic information with our optical 3D motion capture system—how the club and body move, and how fast. And for the first time in a golf lesson setting, we can take that positional data and calcuate a swing’s kinetic performance. It’s why the club moved in a certain way.

3D OPTICAL MOTION CAPTURE With eight cameras capturing the movement of 34 markers on golfer and club we can track the position and movements of the player. Based on that positional data and the path the markers move on, we can study the forces that produced those movements.

The basic camera on an iPhone and a $10 swing analysis app can show the change in a clubhead’s position from address to the top of the backswing and then down to impact. That’s like using a stop watch to keep track of how long it takes Jimmie Johnson’s car to make a lap around the Talladega Super Speedway.

The kinetic outputs from Jacobs 3D show what forces and torques create those movements.

Why is this important?

Because body and club movements aren’t important for their own sake.

Doing something with your body or the club— swinging “from the ground up,” or “lagging it” or “pivoting” or “transferring your weight” or “bracing your left side” only matters if you’re actually changing the way the club moves through space, and the

CHAPTER 1

energy it transfers to the ball.

Until now, we could only guess at what kinds of forces and combinations of torque would change those club movements and energy transfer.

In a way, we’ve been teaching backward all these years. We’ve been trying to get people to change and “improve” their movements to try to get the club to do something different to the ball.

But that’s like telling Jimmie Johnson to steer the car a different way to make it win a race. Steering is part of the equation, and steering completely wrong will cause a crash. But if you don’t understand how to make the engine work at peak efficiency and the relationship between the car’s performance and how the steering system works, you aren’t even scratching the surface of true peak performance.

It’s time to go deeper, beyond what your swing looks like.

Let’s talk about the engine.

We’ll start with the equations Isaac Newton came up with more than 300 years ago—one for linear motion and one for rotational motion: Force = Mass x Acceleration Torque = Inertia x Angular Acceleration What You’re Doing = What You Feel x What You See We’re going to get into what those terms actually mean in a golf swing, but at the most basic level, the two elements on the right side of each equation are the resistance (mass and inertia— what you feel) and what you see happening (acceleration and angular acceleration).

Acceleration is the rate of change in an object’s velocity. To create this change in velocity, something has to influence an object to overcome its own mass (for linear movement) and moment of inertia (for rotational movement).

For linear motion, that influence is a force.

For rotational motion, that influence is a torque.

You’ve almost certainly heard those terms before, but probably not in the golf sense.

Let’s break them down.

What is force, besides something Luke Skywalker is supposed to use? And what is torque, oth-

er than one of those numbers car companies use to brag about an engine?

A force has both magnitude and direction and when unopposed will change the motion of an object. A great example of a force is something like pushing a car that is out of gas down the road. Just as a force is a pull or a push, a torque is the twisting of an object. Turning a door knob or tightening a bolt with a wrench are great exmples of torquing an object. When you twist a door knob to the right with your right hand your thumb works up while your fingers work down. When you twist the door knob to the left the opposite happens and your thumb works down and your fingers work up. The magnitude of the twist determines if you’re turning the knob slowly (as if you’re trying to sneak out), or hard (as if you’re angry and trying to leave!), or anything in between.

You can categorize the movement of the club during the swing into two varieties—linear and angular movement.

Imagine holding the club out in front of you, with the shaft standing straight up. If you push the whole club out from your chest and pull it back toward you without letting it turn or twist, that’s linear movement. If you turn or twist the club, that’s angular movement.

How a player combines those forces and torques determines how the club moves during a golf swing.

In order to understand these forces and torques and how they’re operating during a swing, you have to have a system to define and measure them. In the early 1990s, Frank Thomas of the USGA commissioned Dr. Steve Nesbit to figure out what a player’s physical contribution was to the swing. Steve describes some of that adventure in his foreword to this book.

As Dr. Nesbit mentioned in the foreword, one of the most important findings in his research was the path the hub takes during a golf swing and how that is intertwined with the forces and torques applied by the golfer.

In Chapter 2 we will discuss the hub in detail but let’s define it here: The hub is center point of where the golfer grasps the club. All the movements of the body culminate at this hub which is

FORCES & TORQUES

where the golfer applies his or her linear forces and rotational torques to the club. Let’s start with the linear force. It is the dominant action on the club and it changes direction and magnitude throughout the swing. During the downswing, the force begins outside the path of the hub and then changes direction to point toward the golfer by impact. As the velocity of the club increases, it requires more force from the golfer to change its curve.

Every golfer moves the hub and applies force differently to the club. This explains why every player looks different when you’re watching golf on

THE HUB

TV or playing with your weekly foursome. There are some commonalities amongst the best players in the world and when we start to see trends they can be labeled as fundamental to an elite swing.

Let’s take a look inside the Jacobs 3D software to see how different golfers apply their force to the club on the downswing. A major champion on the PGA Tour swinging a driver, an LPGA player hitting a 6-iron, a PGA Tour multiple winner using a driver, a club pro hitting a 7-iron, and a 20 handicap also hitting a 7.

The center point of the golfer’s grip is the hub of the swing. The hub is where the player imposes his or her will on the club, and where the actions of the body culminate. In Chapter 2, we’ll talk about how the movement of the hub influences the swing.

CHAPTER 1

FORCES & TORQUES

LINEAR FORCE

A golfer applies a linear force to the club, and that force changes direction and magnitude during the swing. The avatar left, of a PGA Tour player, shows the downswing with a yellow line representing the direction and magnitude of his linear force. Every player has different kinetics, but there are some common traits that are fundamental to every good player.

CHAPTER 1

MAJOR WINNER—DRIVER

The pink dots represent the path the clubhead takes from the start of the downswing to the follow-through.

The yellow lines represent the shaft of the club, while the light blue arc is the path of the hub.

The white arrows are called “quivers,” which illustrate the magnitude and direction of a player’s applied force.

Notice the initial direction of the force, the shape of the hub, and how the player redirects the force in a spiral shape. We’re going to talk much more about all of these factors.

FORCES & TORQUES

LPGA TOUR PLAYER—6-IRON

When you start to compare the differences between iron and driver swings, you see how the length of the club plays a role in how the player is able to move the club. This LPGA player is one of the best in the world, and her hub path and linear force spiral was very consistent from swing to swing when captured in the Jacobs 3D studio.

MULTIPLE PGA TOUR WINNER—DRIVER

Here we changed the perspective so that you are looking from in front of the player. Notice how the initial shape of the hub path begins to drop vertically while the player is applying force back and away from the target— directly away from you, the viewer. A player’s height plays an obvious role in how they move the hub and force the club. This player is shorter than many others, and has a unique hub shape because of it.

CHAPTER 1

CLUB PRO—7-IRON

This club professional has a shorter backswing length than the tour players we’ve been examining. Notice the position of the yellow shaft lines at the top of the backswing, and how they are short of parallel to the ground.

The force quivers show this player is doing everything he can to delay the outward movement of the club on the downswing.

20 HANDICAP—7-IRON

This 20-handicapper is a senior player who struggles to produce distance. He clearly has the shortest swing of any player on these pages, and produces the least amount of force. The white quivers are short—which means they aren’t of a high magnitude—and they don’t have a very spiral shape. Jacobs 3D provides a layer of analysis for these very different swings that the game has never seen.

FORCES & TORQUES

TORQUE

ALPHA

The twisting action a player adds to the club in The side to side rotation of the club is the largaddition to this force makes the club rotate—which est and most dominant one —so it is called Alpha it has to do to get from back behind your head to (after the Greek letter for ‘A’). the ball. To help describe the rotation of the club, Dr. Nesbit broke the rotation down into three catAlpha Example: egories. Those rotations are called alpha, beta and If you held a toy airplane by the tail and yawed gamma: the plane side to side as if you were shaking the passengers to their left and right side of the plane, you are imparting Alpha rotation.

CHAPTER 1

ALPHA

Alpha is the main swinging action of the club.

Alpha rotation is a key contributor to transferring hub speed into clubhead speed, managing the path the club moves on and squaring the clubface for impact. The green arrows represent the positive alpha rotation direction while the red arrows display the negative direction.

FORCES & TORQUES

BETA The rotation that changes the “pitch” of the club is called Beta (for the Greek ‘B’). The easiest way to understand Beta is to look at a swing from down the line with the golfer in the address position.

Beta can be a complicated subject due to the fact that lifing the club up and down with force vs rotating the club up and down with torque is quite complex. To add an extra layer of complexity, changes in wrist angle does not necessarily coincide with changes in Beta rotation.

Beta rotation serves as the classic “lag angle” in the early downswing and the classic swing plane angle at impact.

CHAPTER 1

BETA

Beta is the ‘pitching’ rotation throughout the swing. The pitch of the club (Beta) is the classic lag angle in the early downswing but by the time impact is reached it now becomes the impact swing plane angle. This clearly demonstrates how a golf swing is driven in six degrees of freedom and how difficult the golf swing is to master.

The green arrows represent the postivie Beta rotation direction while the red arrows display the negative direction.

Please refer to the ‘Science of the Golf Swing’ textbook for a deeper discussion on Beta.

Beta Example: If you once again held a toy airplane by the tail and tilted the nose of the plane up and down, you would be changing the pitch of the plane. This change in pitch is Beta rotation.

Note: All the rotations were calculated using classical mechanics. The rotation directions were then chosen to best help the comprehension of the golf world.

FORCES & TORQUES

GAMMA

Gamma rotation is the twist of the grip and shaft about itself. Gamma will have an effect on the squaring of the clubface.

GAMMA The rotation imparted from twisting the grip of the club is called Gamma (for the Greek ‘C’). If you held the club straight out in front of you and did nothing except turn the handle like a door knob and opened and closed the shaft, you’re creating Gamma rotation. We have seen some very interesting applications of Gamma torque in different players. We will show some common samples at the end of this chapter.

The quickest way to get a sense for the differences in Alpha, Beta and Gamma is to hold your

cell phone out in front of you flat, so the screen is aimed at the ceiling. If you turn the phone back and forth horizontally, so that the screen still faces the ceiling the phone swings to the left and right, that’s Alpha. If you hold the phone the same way, and tilt it so that the phone moves like a teeter totter, you’re seeing Beta. If you twist the phone around so that the screen rolls towards the ground, you’re seeing Gamma.

As you can imagine, there are many combinations of these forces and rotations. Those combinations produce super-efficient, powerful swings like Louis Oosthuizen’s, and they produce inefficient, weak swings that 30 handicappers use.

CHAPTER 1

I could write an entire book on how forces and torques work together—and that’s the Science of the Golf Swing textbook—but for the purpose of introducing the subject, let me start with a few examples.

It makes sense that a player would want to transfer as much energy from the club head into the ball as possible, right? But how do the forces and torques work together to complete the transition from backswing to the downswing—the beginning stage for the transfer of that energy?

Most players think the top of the backswing is a definitive pause, followed by a race to hammer the handle of the club down at the ball as hard and fast as possible. By forcing and torquing the club this way, you never completely transfer the energy from the golfer to the end of the club head, where it can actually produce more distance.

The best way to describe it is to compare what would happen if the average player let go of the grip right as he or she started the first move of the downswing to what would happen if a tour player like Oosthuizen or Rickie Fowler (or almost any great player, really) did the same.

For the average player, the precursor to an “over-the-top” move is literally an over-the-top force creation. The bad player will force the club to start in a direction out in front of them—somewhere over the ball. If he or she let go of the handle, the club would hit the wall of the driving range stall in front of him or her.

Compare that to what the tour players are doing and it’s like you’re watching a different sport. At the first move in the downswing, a player like Oosthuizen is forcing the club in a way that would cause him to fling the club high and far in the opposite direction of the target.

To see this for yourself, get in your stance and make a backswing. Stop at the top, and turn your head to the right. The good player is forcing that club so that it would fly right over the bag sitting at the back of the hitting bay.

What makes Jacobs 3D so interesting and useful is that we can see these exact differences in the timing and intensity of these force applications.

For example, the timing of the different torques during a swing makes a huge difference in the magnitude of the motion those torques produce. There are times in the swing when the club is very receptive to being torqued, and times when it has a lot of “rotational resistance”—or opposition to being torqued.

Try to torque the club when there is lots of rotational resistance and you won’t get much response. Do it when the club is open to being moved and you can really change your motion.

This is where force and torque information is transforming golf instruction. You need to be working on the appropriate mechanical concepts for your swing, but understanding this concept of rotational resistance gives you a much better chance of changing the way you actually swing the club.

FORCES & TORQUES

FORCE DIRECTION

Every player knows that the transition from backswing to downswing is a key component of consistency. The length of the backswing will play a role in how you can force the club, but the most common mistake average players make at the start of the downswing is forcing the club toward the ball instead of away from them.

CHAPTER 1

Let’s talk a little bit about some of the gammatorque graphics you’re going to see through this book. These images, produced by the Jacobs 3D software, are of three different players’ swings.

At first look, it probably seems confusing. But the curved lines and the spikes show very specific things. This graph shows the hub path in blue— which we’re going to describe in much more detail in Chapter 2—and the direction and intensity of the gamma torque being applied to the club during the downswing. The purple curve is the movement of the clubhead and the yellow lines are the shaft of the club.

The spikes coming from the clubhead path are called “quivers,” and they can be configured to show things two ways. If they appear at a consistent height, they’re showing direction. When they change heights, as they do here, they’re showing the relative magnitude of the torque in addition to the direction of whether it is towards the target or away.

So what does it show?

GAMMA TORQUE PLAYER 1—IRON SWING

It traces how the player is moving his hub, and both when and how he is applying gamma torque to the club. In player 1, notice that at the start of the downswing there aren’t any quivers. This means that he is not applying any gamma torque to the club. As the downswing progresses, the quivers grow in a positive direction (pointing outside the purple path)—which means that this player is applying a closing twist to the club.

As he nears impact, the positive gamma torque begins to diminish and is negative (pointing inside the purple path) just after impact. This is something we’re going to be talking more about in the Science of the Golf Swing along with Alpha and Beta torque quivers.

In Chapter 5, we’ll look at three swing reports to give you a sense for what there is to learn from the software. With some practice and more familiarity with these graphs, you’ll soon have much more of an understanding about what happens in a golf swing—and how the differences in forces and torques translate into movement.

The quivers show that the player doesn’t apply any gamma torque at the start of the downswing, then starts to ramp up more gamma torque before slowing that torque down by impact. Positive gamma torque is a twist that closes the grip and shaft toward the ball, while negative gamma is a twist in the opposite direction. Notice the unique shape of the light blue hub path right after impact (the dot at the bottom of the image). The player is performing a significant wrist and forearm roll, which changes the shape of the hub path. This player is a PGA Tour winner.

FORCES & TORQUES

GAMMA TORQUE PLAYER 2—DRIVER SWING

Similar to the other players, this golfer starts applying a positive gamma torque shortly after the hub has started its downswing. The positive gamma torque diminishes well before the club reaches the ball and is actually negative. This negative gamma torque before impact is extremely common. This player is a PGA Tour winner.

GAMMA TORQUE PLAYER 3—IRON SWING

This 6-handicapper shows a similar trend in how gamma torque is applied to the grip. The negative gamma torque before impact shows that the twisting action of the player is an attempt to slow down the gamma rotation of the shaft and grip. The grip and club will be experiencing a very fast positive gamma rotation at the bottom of the swing. Keep in mind that gamma torque is a small magnitude torque—which means it doesn’t require much effort to produce. Rotational Resistance (moment of inertia) is covered in full detail in the Science of the Golf Swing textbook. You will come to find out that Alpha, Beta, and Gamma all have different rotational resistances.

CHAPTER 2

The Hub Path

If you want to start a golf argument, you don’t even need to use words. Just hold up a still photograph of a tour player at some point during his swing.

You’ll get teachers and players talking about what the tour player is doing (or not doing), and whether or not it’s the “ideal” way to swing a club.

Everybody wants to see positions, and argue about those positions. Who is doing what with their wrists? Feet? Hip tilt? Shoulder turn? But the problem with that exercise is that it misses what we’re discovering is the main indicator of a great golf swing.

Jordan Spieth, Rory McIlroy, Lydia Ko and any other tour pro aren’t great because they do some magical thing with their swing. And, sorry to say, there isn’t some secret foot or hip move that the average player can copy that will transform his or her game.

What separates great players like Jordan, Rory and Lydia from everybody else is the individuality of each of their hub paths—the route the hub (or, place where the hands connect to the club) takes through the swing.

Do they make certain body movements to make their hubs do what they do? Sure. But all of those body motions are in pursuit of one goal— making the interaction point between the golfer and the club, the hub, move in a certain way.

To get the best out of your swing, you need to understand what your hub is doing, and how to make that hub move in a way that produces the most energy transfer from your body into the club

and ultimately into the ball.

Why does this matter in golf instruction?

Because if you’re trying to change something in your body movement that doesn’t translate into a more efficient or consistent movement of the hub, you’re working on something that literally doesn’t matter.

It would be like discovering your house has a giant hole in the roof and deciding to paint the outside walls. You’re making changes, but you aren’t fixing any problems.

I’m sure you’ve thought about your grip—at least in terms of how you put your hands on the club.

But in this chapter, I’m going to show you how to think about it in an entirely different way. It will change how you consider your swing—and how you improve it.

THE HUB

The hub is the location on the handle where the golfer imposes their will on the club. The path that the hub takes during the swing is closely intertwined with the ability of the golfer to transfer energy to the club.

Physics books have always assumed that the path of the hub was circular enough to model it as a constant radius. Dr. Nesbit found that the subtle, non-circular movement of the hub is an indispensable element of the swing.

CHAPTER 2

As we talked about briefly in the last chapter, the “hub” in Jacobs 3D terminology is the linkage point between the hands and the handle of the club. It’s the center point between the hands—and the place where the golfer imposes his or her forces and torques on the club.

It sounds obvious to say that the hub controls what happens in the swing, but you can go back through 150 years of golf instruction and read plenty about the body-controlled swing, the inside moves the oustide, swing connection, biofeedback, and a million other approaches that diminish the importance of what’s happening at the hub.

You won’t hear that here.

The action at the hub is the most important, and most fundamental way the golfer hits a shot.

And after studying hundreds of swings on both GEARS and Jacobs 3D, it’s fascinating to report that every player has a hub path that moves in a unique shape—like a fingerprint.

That path can determine whether or not you’re getting the most energy transfer out of your body. It’s the reason why 5-foot-9, 165-pound Rory McIlroy can carry the ball 320 yards off the tee, and 6-foot-3, 220-pound Nick Faldo was 80 yards shorter.

In the broadest terms, the movement of the hub—the hub path—plays a huge role in controlling the outward movement of the club on the downswing. If you equate this outward movement of the club to the cracking of a whip, it’s the actual act of the end of the whip speeding up and cracking.

Good players generally move the hub path in a way that causes the club to stay back and close to the body at the beginning of the downswing, and then they make a sharp curve with their hub to allow the club to swing out and snap around down near impact. Poor players tend to do the opposite.

Again, those are the broadest, most general terms—there are many ways to move the hub, and many reasons for swings to work (or not work).

Later in this book, you’ll see a variety of scouting reports on real players and their hub paths, along with analysis of their movements.

To get the most out of your swing, you will want to optimize your hub path. That means you

will be moving the handle in a way that transfers the maximum amount of energy from your body into the club at the right time so that energy can be transferred into the ball.

Many teachers (and scientists) have thought of the shape of the swing and the hub path as circular—with each radius on the circle an equal length.

But the hub path isn’t perfectly circular.

THE HUB PATH

The blue curve is the backswing path and the red curve is the downswing path. You will learn in this chapter how to map out your own hub path using a variety of techniques.

The radius of the hub changes length throughout the swing, and how it changes is an indicator of the skill and or weakness of the player.

This change in radius changes the actual center point around which the hub is moving at any given time. This fundamental swing element is called the center of curvature.

On a basic hub path graphic from Jacobs 3D

THE HUB PATH

DOWNSWING AND FOLLOW THROUGH

As you can see here, the blue hub path isn’t a perfect circle. The subtleties of its shape are fundamental to each player’s swing style. The assumption that the swing is circular enough to consider it a constant radius has led to many mistaken conclusions about the mechanics of the swing.

like the one shown above, you can see the trace of the hub movement through the downswing.

By linking that movement with a variety of other measurements from the software—like forces and torques—it becomes very clear what kinds of movements produce the most efficiency.

One huge swing “myth” to get busted by all of this study is the concept of lag—at least in terms of how that word has been used to talk about golf swings. People equate lag with “holding” the club back in the downswing with the hands and the wrists. By “delaying the hit,” or intentionally hitting the ball with the hands pushed ahead of the clubhead, players are supposedly producing tour-level power.

That’s totally false.

“Lag” happens in good swings, but you have to know how to engineer it. The quickest way to delay the outward movement of the club at the start of the downswing is to make your hub path travel with the least amount of curve.

Think about how you would use a fishing pole to cast a lure out into the lake. When you start to cast the pole, your body moves first and the handle moves in a straight line—which helps preserve the

“lag” in the tip end. Then you have to make a sharp down-and-back curve with your hands to sling the tip forward. That’s the same action you use to transfer energy in your swing (and something I demonstrated in an April 2016 Golf Digest instruction article called Get a Handle on Your Game).

This mid-to-late downswing transfer of energy is badly misunderstood. When the player creates a curved shape with the hub path, this will promote the twisting of the club in a way that makes it want to move out, or “un-lag.” This is something you want to happen! When the club moves out at the bottom, it is getting the full benefit of energy transfer from the player. If you try to restrict or

CHAPTER 2

hold the angle, so to speak, you’re breaking the kinetic chain, and fighting against yourself.

Poor players are trying to make their hands go as fast as possible in a straight line toward the target or ball while the club is trying to swing out.

The hub shape you would see in that case is much flatter near the ball.

These facts combine to create all kinds of problems for players—both professional and amateur. If you’re determined to believe that lagging the club intentionally is the way to play, the only way you’ll be able to consistently hit the ball is to skew the direction of your swing hard to the left or right near impact. And if you’re using a launch monitor— which measures path and clubface—you’re going to get trapped in a feedback loop.

To make the numbers change, you have to change your swing direction and attack angle constantly. When you play the numbers game on the club down by impact when the resistance of the club is extremely high, you will start to produce erratic results—even if the TrackMan is telling you you’re “zeroing out.”

REDIRECTING THE FORCE AT THE BOTTOM

Poor players try to force the club in the direction of the red arrow at the bottom of the swing, while good players are forcing the club in the direction of the green arrow. Tips like “hit down on the ball” and “get your hands in front” have given players the wrong idea about what should happen in a mechanically efficient swing. Great ball-strikers are changing the direction of the club by moving the hub path in a curved spiral down by impact.

Compare that to the elite player, who is curving the hub path sharply upward to crack the whip, so to speak. This continual curving or spiraling action of the hub path is a signature move of the best players on the planet. In fact, you’ll see the best junior and female players go right up onto their toes at impact to try to help promote this curving action. The club has so much velocity near the ball that they need to recruit all that they can to get it to change its curve.

THE FLY SWATTER

The Fly Swatter is a Jacobs 3D parameter that takes a unique look at the hub path. The entire downswing and follow through is flattened into a 2D picture.

Once flattened, the relationship between the hub path and the clubhead path can be further analyzed.

Understanding all of this is a bit like understanding the physics of how an engine makes a car move. It’s just one piece of the puzzle. But it’s a big piece.

The next obvious question for the average player trying to improve his or her understanding is, how do I know what my hub path is if I don’t have a GEARS system and Jacobs 3D?

THE HUB PATH

With a smartphone and a cheap swing capture app, you can get a decent representation of your hub path in two dimensions on video. It’ll take a little acrobatics from a friend to get the best result, but it isn’t hard.

You have two choices for making a capture.

The first method—the basic face-on view—is much easier to do, but it provides less helpful information.

The image shown below is a swing sequence shot from the basic face-on view. When you make a sequence like this, positioning the camera in the right place is vitally important to avoid as much skew in the end result as possible. Set the camera so that it is at an exact right angle to where the club will be at impact. Letting it drift a few inches

FACE-ON VIEW

behind or in front of the ball position will provide a false image.

Once you have a good capture, toggle the swing frame by frame to the top of the backswing—defined as the highest point the handle reaches in the backswing. From there, make a dot or small circle over the spot where the two hands are joined on the grip.

Now scroll through the swing frame by frame, making the same dots on top of the hub as it moves down and around. You will start to see a collection of dots that represent the hub path in two dimensions. Start taking note of how the dots and the hub path curve. The subtle changes in curvature have major implications on the outward swing of the club.

CHAPTER 2

The second method will give you much more information about the hub path, but you need to be able to film your swing from directly above. You want it to be pointing straight down onto the center point of the club at impact.

To get this angle, ask a friend to use a stepstool and a tripod or selfie stick, or connect a webcam to the wall or ceiling of a room or garage. You’ll need to get creative if you want the best view.

On the next page at right, you’ll see the same

HUB PATH FACE-ON VIEW

swing as in the first example, but shown from this new angle. Now, draw the hub path frame by frame through the swing the same way you did in the last example.

When you’re done, you’ll see a much more intricate hub path than before. You’ll be able to see many of the subtle movements that happen down by the ball, and get great information on what you do—and need to do.

ABOVE VIEW HUB PATH

THE HUB PATH

ABOVE VIEW

Looking down at a right angle to the center point of the club at impact

CHAPTER 2

The Jacobs 3D software measures the hub path in three dimensions—and shows the only true representation of what the golfer really does. When you see these graphs, you can start to understand just how complex this element of the swing really is.

The swing shown here is the same one graphed out in two dimensions in the first two examples.

But this time, the hub path has been rendered by Jacobs 3D. Understanding what your path is doing is just the first step in the process. The next hurdle is figuring out the what and the when of improving that path. You need to know what kinds of adjustments are necessary to optimize that path, and also when to apply those adjustments during the swing.

One of the coolest measurements to come out of Jacobs 3D is the combination of ratios that show the times the swing is most susceptible to an application of torque. In other words, we know the points in the swing when changing your movements will have a large impact on what happens to your club, and when those same movement changes will have little or no impact—or even a negative impact.

“Timing is everything” might be one of the oldest clichés in the English language, but in the post-modern world of golf instruction, it’s even more true than most people realize!

HUB PATHS

The images shown on the next pages are from the same swing represented by the two-dimensional avatars we’ve just been analyzing. Here’s where you will get a true glimpse of the difference between two-dimensional (and even lower-end 3D) analysis and what is possible with Jacobs 3D. As the graphs unfold, you’ll see a variety of fascinating elements that can’t be detected by video, still photographs or the human eye watching in real time. At left is a face-on rendering of the same player’s swing. At first glance, it might look similar to the twodimensional renderings, especially with the way the hub path moves at the start of the downswing. But as you’re about to see, there’s a vast amount of additional detail we can now identify.

THE HUB PATH

JACOBS 3D HUB PATHS

This image is the same hub path from the previous page, but rotated so that the frame of reference is from below.

It’s as if you’re the golf ball, and you’re looking up at the swing. Here you can see just how much the hub path, shown by the blue dots, is moving in three-dimensional space. If you’re trying to describe the movement of the hands as a circle--like most golf instruction from the last 150 years—you’re not getting a true representation of what golfers actually do.

CONSTANT RADIUS

This radius graph shows the change in a golfer’s hub radius throughout the swing. The peaks and valleys of the curve prove that the radius is always changing. The black line represents what this movement graph would look like if the swing happened with a constant radius. In simplest terms, any analysis that relies on a constant radius is going to be inaccurate. That just isn’t what real golfers do.

CHAPTER 2

JACOBS 3D HUB PATHS

This software parameter isolates the path of the hub and the location of the shaft.

This isolated view helps indentify the interaction between the hub and club in all three dimensions.

HUB OPTIMIZER

In this graph, we use color codes to quickly identify how the golfer is changing the curve of their hub path at any instant in time. When the hub is green, the golfer is making less of a curving action and “widening” the hub path. When the hub is red, the player is adding more curvature to the path of the hub and making it “sharper.” The amount of instantaneous curvature of the hub is an indicator of the relative skill or weakness of the player.

THE HUB PATH

DOWNSWNG AND FOLLOW-THROUGH HUB PATH CENTER OF CURVATURE

CHAPTER 2

CHAPTER REVIEW These images are just some of the Jacobs 3D parameters that analyze the intricasies of the hub.

The take-home messages are: • The golfer does not swing in a circle.

• The shape of your hub path is unique and therefore a one size fits-all golf swing method would be difficult to apply.

• The forces and torques on the club are closely intertwined with the curvature of the hub path.

• The combinations of widening and shortening the hub curvature is an indicator of the golfer’s skill and or weakness.

• You can map your hub path out with 2D video but keep in mind the limitations.

CHAPTER 3

Work & Power

they can potentially hit a golf ball.

Strong bodybuilder-types might have big powerful muscles but their range of motion and the speed at which they contract might be better at pulling a stump out of the ground instead of making a club move fast. And a small, slight guy like Rickie Fowler can stand up there and carry the ball 300 yards. This matters for a few very important reasons. First, it reinforces the fact that there is no single “perfect” way to swing a golf club. There’s an ideal way for somebody built like Ernie Els, with Ernie’s physical abilities, to do it, but that method isn’t the same one Arnold Palmer or Jordan Spieth should use.

Second, the more we can understand these power factors and how they work together, the better we can get at figuring out how to get the most out of each individual player’s body and swing.

In simpler terms, we can figure out what swing you should use to get to your power peak.

The “problem” of producing power in a golf swing is an important one. Power consists of the rate at which you do work.

Those terms have very specific meanings in the world of mechanics, and it’s important to talk about them briefly here.

All kinds of body types and swing shapes can If you put this book on the table and pushed it produce good golf shots. But they all do it different toward the middle of the table, you’re doing what’s ways. We can make some generalizations about some parts of the game—like grip or balance—but called work.

Work is defined as force times distance. The many of the pieces are very particular to the player. amount of work, or movement, you produce is For example, if you’re built closer to Rickie Fowler’s frame, you’re going to do things differently directly related to how and how much you move the book. than Ernie Els does—in the same way Steph CurIn the simplest of golf terms, linear work is the ry and LeBron James do things differently on the physical distance you move the club during the basketball court. swing.

Muscle density, limb length, joint size and If you move this book toward the middle of bone structure are just a few of the physical factors the table and also twist it around at the same time, that determine exactly how a certain player can make certain moves. Even something as seemingly you’re doing both linear work and angular work.

Angular work is the amount of torque in the esoteric as pelvic structure is a big determining swing times the amount of angular displacement. factor in exactly how a person can turn and tilt.

In the simplest of golf terms, angular work is These facts are part of what makes golf so fascithe amount of rotational movement you impart nating to watch on the tour level, and so hard to emulate. It is almost impossible to look at a person onto the club with applied torque. standing there in street clothes and see how far

It is very easy to chase swing tips forever.

Watching the best players in the world on the professional tours isn’t like watching the NBA or NFL. You see players who aren’t necessarily freak physical specimens doing things it seems like anybody should be able to do. And so most players keep searching for that one tip that will suddenly take five shots off their handicap. The problem?

CHAPTER 3

The graphic on the right really isolates the difference between the linear and angular movement of the club. Let’s say you swing the club back to the top of the backswing, and it is in a position parallel to the ground. You apply your force at the grip and that point of application is used to decipher the distance traveled. This distance includes all three dimensions: up and down, side to side, forward and in back of you.

Because the point of application is at a distance from the mass center of the club, there will be some angular response which will rotate the club.

This force x distance system is what we call linear work.

Once we know the linear work and the response of the club to that application, we can then analyze the torque that the player applies to the club. This torque X the angular displacement is angular work.

In the Science of the Swing textbook, we breakdown all of the torques and angles that go into this angular work equation. For this sake of this introductory book we will cover just the basics of how a golfer applies these principles into their swing and we will let the textbook dig deeper.

LET’S SIMPLIFY

A swing obviously needs a combination of these two kinds of work to function. The club needs to move away and then toward the target, and it needs to rotate in tandem with this linear movement. The best swings use linear movement in a way that produces the fastest and most precise angular work.

When you start talking about things like “fast” and “speed,” you’re adding a time component to work.

Work along with a time component is a measure of power. Power is the ability to do a certain amount of work in a certain amount of time.

Here’s a simple description to bring these terms into focus.

Say you need to make a one-mile trip from your house to the grocery store. If you walk the mile, you will get to the store in 30 minutes. If you run, you can get there in 10. The amount of work produced by the time you get to the store is the same—1 mile. But the power you have produced by running is three times what you would have produced by walking.

Players with long arms and flexible bodies can increase the overall linear and rotational displacement of the club—therefore doing more work.

Other players who move the club less, will need to do it faster to keep up. The longest of the long hitters do both—increase the amount of work, and increase the speed at which that work is being done.

All of this is a long way of saying that the key to increasing power is learning how to produce work in the club at an increasing rate. In this book, we’re examining the movement of the club—not the movement of the body—and the most efficient movement paths. In the next phase of this study, we’ll do the same measurements on the body itself.

You’ll be able to see how Rickie Fowler’s (or any other player’s) club moves through space, what

WORK & POWER

forces and torques he uses to make the club move, and how he uses uses his body to produce those forces and torques.

By itself, that information doesn’t solve the universal “power” question, because Rickie’s combination of physical traits and skills are unique.

The real job comes sorting players’ physical traits and club movements and figuring out which pieces help an individual player optimize what he or she does.

In other words, copying Rickie Fowler wholesale almost certainly won’t get you more power.

But maybe Rickie does two or three things that can help, along with things that other players might do.

Finding that ideal mixture? Now that’s power.

Dr. Nesbit has come up with a complex formula that optimizes based on an individual’s kinetic and kinematic constraints.

What does that mean in English? It isn’t a recipe for the specific ways a player should mechanically move his or her body. It’s a blueprint of the most efficient hub path movement for the improvement that player is trying to achieve.

After just a few swings in my motion capture studio, our formula can determine the maximum physical capability of a player—and what aspect of power generation needs improvement. For example, we might identify that a player is too linear, too long. In real life, that would look like a player trying to lag the club long into the downswing. The result from the optimizer shows exactly how that player needs to modify his or her hub path to reduce that error—then it becomes up to the teacher to figure out the strategy to make that mechanical change.

An interesting aside: “Casting” has always been identified as one of the fatal flaws in a swing, and thousands of teachers have taught that it happens when a player “throws” the clubhead away too early in the downswing. In other words, it has been classified a torque-related problem.

But in reality, casting most often comes from the opposite issue—a linear one. It’s a misapplication of linear force—forcing the club in the wrong direction—that makes the club “throw” outward harder and even more at the wrong time!

HUB OPTIMIZER

This image is from Dr Nesbit’s paper “Kinetic Constrained Optimization of the Golf Swing Hub Path.” The optimization goal was to maximize the club head velocity at impact within the kinetic constraints determined for each golfer during their swing captures.

CHAPTER 3

INSIDE THE HUB

What does this mean for you?

Start assessing where the club is in relation to the hub path. How long does it stay “inside” the hub, and when does it move outward? Changing that relationship will get you closer to optimizing your power production.

What does it mean to be “inside” the hub?

When the shaft of the club is on the side of the hub closest to you.

The club tends to move outside the hub for tour players at a different time than amateurs. Most amateurs are trying hard to prevent the movement of the club outside the hub because they have been told not to cast—this is actually slowing the clubhead down in the long run.

OUTSIDE THE HUB

WORK & POWER

By the time the shaft begins to move to a position outside the hub, the good player’s hands will have been slowing down, which transfers the energy outward to the head end. Poor players are trying to make the hands speed up at this point, which throws off the timing and is like trying to crack a whip while moving both ends of it in the same direction, it doesn’t work.

A fascinating statistic is that amateurs and tour players only move their hands at a peak speed of between 13-22 miles per hour as a rough average.

You will often see amateurs with just as much of a hand speed peak as a tour player, yet the clubhead speed can be 30 miles per hour different. How can this be? The clubhead speed comes from multiplying that hand speed during the transfer of energy to the club which proves the importance of the spiraling hub path.

This chart on the right is the clubhead and hub path velocity on the downswing until time zero which is impact. You can see that the slope of the clubhead continues to rise as the hub path velocity starts to level off and drop. This is a tour player’s driver swing.

We’ve talked being “closer to you” and “outside” the hub, but there is also another important aspect to consider—away from the target line and toward the target line, or “behind” or “in front” of the hub. This is where we start talking about the concept of swing planes, and leads us to the next chapter.

TOUR PLAYER

Behind hub

In front of hub

CHAPTER 4

Relative Swing Plane

By now, you’ve probably figured out that there’s a lot more to the golf swing than you can see by just watching casually.

It’s like trying to predict how much horsepower a strange new car has by watching it roll up next to you at the stoplight.

Because of everything that happens “behind the scenes,” players and teachers have for years tried to come up with ways to simplify what can be very complicated, confusing concepts.

The most simplified one of them all might be swing plane.

It’s a subject I took on in my first book, Swing Tips You Should Forget. The term itself, “swing plane,” is one that gets thrown around more than almost any other teaching term.

I can see why. The idea that a player swings (or should swing) on a constant plane from the top of the backswing down through the ball is attractively simple. Just put the club on Ben Hogan’s imaginary plane of glass—the one resting on your shoulders—and you’ll be able to hit the ball consistently well.

Or, in more modern, launch monitor inspired terms, if you swing the clubhead on a consistent swing plane in the impact phase down by the ball, you’re going to be a good ball-striker.

Unfortunately, the science just doesn’t support the first theory, and the second theory has obvious merit but has left players and coaches with an incomplete formula for how to accomplish that consistent “impact phase.”

When you boil the swing down to a basic planar motion, like dozens of teaching methods,

books, videos and biomechanists have done over the years, you cook out a very important, basic fact about any golf swing—even one that looks like it is perfectly “on plane,” in the classic sense of the term.

In a golf swing, the hub path and the clubhead path will move on different planes. And those planes aren’t just the simple steep-or-shallow vertical ones you’d map out from the standard downthe-line view on a video analysis. In fact, you could be swinging the clubhead on the same “plane” as defined by Ben Hogan, but your hub path could be moving in a different direction left or right—something that is impossible to see on regular video.

This can be a complicated idea to get your head around, so let me put it in a different way.

Picture yourself at the controls of an airplane.

You have the control yoke in your hand, and your feet on the pedals. With that combination of controls, you can make the plane go up and down and you can make it turn left and right—or any combination of those movements. You can make the plane gain altitude while simultaneously turning left, or make it lose altitude while simultaneously turning right, if you want.

During your swing, your hub path changes altitude and direction in the same three-dimensional way, and it happens independently of the clubhead. If the hub path and the clubhead aren’t on the same angle at the same time, that difference in angle will produce a response in how the club behaves during the swing—and that response can either help you or hurt you.

That relationship between the plane your hub path moves on and the one your clubhead moves on? That’s the Relative Swing Plane—a measurement that is completely new to the game of golf, but one you’re going to be hearing a lot about in the future.

Why is this important to understand? Because most players make the mistake of equating the movement of their hands to the movement of the clubhead in a direct relationship. Trying to hit down on the ball? Swing your hands at the ball from the top of the backswing. Trying to make the

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clubhead swing down the line longer? Make your hands go down the line as well.

But those ideas are totally misguided, and they’ve caused decades of frustration for players at every handicap level.

With Jacobs 3D, we’ve been able to prove that the best players move the hub path and the clubhead path on what are at times very different planes. And to make the clubhead move a certain way, they move the hub in a very different way— and do it at a different time. And the movements are different with different clubs! The hub path and clubhead planes diverge and match up at different times with a driver than they do with a wedge.

We’re just examining the very tip of this iceberg—you’ll read more about the Relative Swing Plane in the Science of the Golf Swing book—but this discovery goes a long way toward explaining why great players are able to move the clubhead so much more efficiently (and quickly) than lessskilled players.

It’s because they know when to apply the right kinds of forces and torques to make the club head move on the ideal route for their swing.

Going back to the airplane example, how and when you use the controls to make the airplane change altitude and direction impacts the size and effectiveness of the change. If the airplane is going slowly, it’s easier to make it turn and change altitude. If you’re in a steep, fast dive, you’re going to have a lot more trouble changing the airplane’s route.

Bad players swing badly for a variety of reasons, but one common flaw virtually every bad ball-striker has is easy to pick out when you look at the Relative Swing Plane graphs.

However good players move the club, the shape of their hub path and plane is much less erratic. Dr. Steven Nesbit has pointed out very clearly in many of his research papers that the shape of the hub is a prime indicator of a player’s skill. The Relative Swing Plane is an extension of this hypothesis.

Let’s look at some of the diagrams that show different players and their Relative Swing Planes.

You’ll see three different players, with different graphics for each one. Two of the players are current PGA Tour players (and tournament winners),

while the third one is an amateur with a common over-the-top move.

At first, the diagrams might look complicated, but once you get a grasp of what they’re showing, your learning curve will flatten out (on its own plane!).

What makes these diagrams—and what they tell us—so important?

Impact is certainly a big deal, and so is understanding what happens in that split second before the clubhead is coming into the ball. But unless you have an understanding of the Relative Swing Plane and what actions earlier in the downswing produce the action you want in the clubhead, it’s going to be way harder to hit consistently good shots.

Going back to our familiar airplane analogy,consider the difference between landing the airplane gently while flying straight down the runway and banging it into the ground while making a hard turn. Which one of those scenarios is going to be more consistent? And comfortable?

Like I said, we’re just in the early stages of using this fantastic new information in day-to-day teaching. And the question this will all probably inspire is a natural one: What is the “ideal” Relative Swing Plane?

As Dr. Nesbit said in the foreword, the answer is fascinating, but probably not that satisfying.

It depends.

RELATIVE SWING PLANE

RELATIVE SWING PLANE IMAGE GUIDE

As we begin to examine some of the Jacobs 3D generated images on the Relative Swing Plane, let’s first discuss the color coding.

The pink dots represent the CLUBHEAD. The trace of the clubhead path is from the top of the backswing to impact.

The yellow lines represent the SHAFT of the club. When the club is moving slowly (the transition from backswing to downswing) the yellow lines are very close together and therefore appear to have no spaces. With the plots of the club being spaced by time, a slow movement will have a distinct yellow color. As the club starts moving faster, there will be more spacing between the clubs.

The light blue curve is the hub path. Just like the clubhead, the hub path was plotted from top of the backswng to impact. The movement of the hub is clearly seen in the light blue path.

The white circle represents where the golf ball is located.

Figure 1

TOUR WINNER DOWNSWING DRIVER

Figure 1 shows the downswing movement of a tour winner. The clubhead path is clearly on a flatter plane than the hub path in the early downswing. As this player reaches halfway down, notice how the plane of the clubhead path and hub path come much closer together. In the second half of the downswing, the vertical planes don’t diverge much, but there is a very large directional divergence in the hub path. You can see this very clearly in Figure 2 and Figure 3. Figure 4 shows the “underneath” view, and how much this deviates from the standard idea of “plane.”

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Figure 2

HUB PATH NORMAL QUIVERS

Figure 3

THE SUPERIMPOSED RELATIVE SWING PLANE

Here, we’re looking from the target back toward the golfer. White quivers have been added to the analysis, and they show the direction the hub path is traveling. If you look at the relative difference between the hub path and the clubhead path, you can see how the relationship is constantly changing.

This image is destined to become a staple of understanding the physics of the swing. It shows the clubhead path angle and the hub path angle superimposed on top of each other. It clearly shows the instantaneous change in the relative angle between the two.

RELATIVE SWING PLANE

Figure 4

UNDERNEATH VIEW

This is a look underneath the golfer from the perspective of the ground beneath the ball. The view is looking directly up at the golf swing and the changes between the hub path and clubhead is easily assessed.

Figure 5

PLANAR VIEW

This image is what the underneath view would look like if the relative angle between the hub path and clubhead was zero the whole swing and therefore this graphic depicts a “ONE PLANE SWING.” This is an urban legend in the real world of golfing. The idea of it may have helped golfers over the years but a perfectly planar hub path and clubhead path would be very difficult to achieve.

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MAJOR WINNER DOWNSWING DRIVER

With this player, we can see how differently the club is moving in comparison to player No. 1—the tour winner.

This major champion clearly has a much more defined divergence in the first half of the downswing. Figure 7 clearly shows that the path of the clubhead makes a sharp plane change early in the downswing. Figures 8 and 9 just reinforce how much the clubhead path plane changes in the early downswing.

Figure 6

Figure 7

Figure 8

RELATIVE SWING PLANE

Figure 9

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Figure 10 30-HANDICAP GOLFER Figure 10 shows how much steeper this average amateur player’s clubhead path plane is in comparison to the hub path at the start of the downswing. This golfer has to then make a drastic hub path movement in the second half of the downswing—which represents the classic outside-in slice maneuver.

Figure 11 30-HANDICAP GOLFER Figure 11 should really hit home.

Look at the severity of the hub path shape. We can infer from this shape that the player would be having extreme issues with balance and consistent body movement.

RELATIVE SWING PLANE

Figure 12

30-HANDICAP GOLFER Figures 12 and 13 help show just how massive the divergence between clubhead plane and hub path plane is, and reinforces the idea that this relationship is an indicator of skill.

Figure 13

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A Look Inside Three Different Golf Swings By looking at hundreds of swings and crunchOne of the loudest ing that data with the help of Dr. Steven Nesbit, Slayton and Dr. Ryan McGinnis—we’re complaints I hear from Alexander able to identify common themes in the swing. players (or other teachers) This is where it gets interesting—and practical.

We can pick out the things good players do, who question the role as well as what poorer players do. What any player mechanics plays in does in his or her complete swing is fascinating to instruction is that the see, but now we can identify what really matters.

Fixing any golf swing is like finding a needle “stuff” we’ve been talking in a haystack. You have to understand what the about doesn’t have needle looks like, and have a way of systematically searching if you hope to find it. practical application.

With this technology, we’re able to identify the In other words, it’s needle way faster, and dramatically reduce the size haystack. just nerdy technical of the I’ve analyzed hundreds of swings in the software, and I can now see with the click of a graph information that gets in two what interesting wrinkles in the parameters the way of the “art” of or translate into a live swing element that needs more the golf swing. attention.

My goal here is to show you a collection of swings from three different kinds of players, and You’ll never hear me say there isn’t any art to offer some insight on how to look at—and use— playing or teaching. Connecting with a student and the data. You’ll see swings from a club pro who delivering information in a way they can underconsistently shoots in the low 70s, a European Tour stand is a fundamental part of my job. player and an average weekend handicap golfer.

But why does that somehow mean that a golfer After comparing the actual avatar images with the who bases his or her swing on anecdotal evidence graphs those swings produce, I think you’ll see or second-hand information passed down through pretty quickly how interesting (and valuable) this the years is using “better” information than a golfer kind of information is, and how it identifies and who uses mechanical principles? predicts what kinds of things happen to the ball.

I’ve been a full-time teacher for more than Some background on the players: The club 20 years, and I’ve given more than 25k lessons. My professional is my friend Steve Haggerty, who has customers would not come back if I couldn’t proplayed good golf for a long time. His low competvide practical application for all of the information itive score is 67. He’s in his mid-40s, and stands we’ve been talking about over the last four chapters. 5-foot-11 and 165 pounds. He struggled with an The information from Jacobs 3D shows what occasional block, and he came to see me to try to real players do with real swings in real life. For the find the small details that would fix both that block first time, you aren’t just looking at the result of a and the compensation for it—a hard hook. He had motion, but what causes it. The images in a video about 84 miles per hour 7-iron clubhead speed (or even the avatars in GEARS) are revealing mowhen we first started together. tions and positions. Jacobs 3D tells you how you The second swing comes from a European Tour made the motion—not just a description of that player who has been one of my favorite students to movement. work with. He’s 6-foot-3 and 200 pounds, and he

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swings the 7-iron you see in this data at 93 miles per hour. That translates into a driver swing speed of 115 miles per hour.

The third player is a high-handicap weekend golfer who plays to a 20. He has many of the same swing characteristics average players struggle with all over the world. He’s 5-foot-9, 170 pounds and swings the 7-iron 77 miles per hour.

We used the GEARS system to measure each player’s swings and provide the data points Jacobs 3D uses to produce the graphs you’ll be seeing. You

can match the movement of the avatars to the corresponding graphs.

The best way to develop your skills at analyzing the data is to match movements you see in the swings with those fluctuations in the graphs. You’ll start to get a sense for the way swings move. You’ll see that many of the “fast fixes” you hear about in instruction are happening way too late.

They’re focused on the effect, not the cause. It’s time to talk about the swing in a different way.

Let’s get to it.

FACE-ON SEQUENCE: STEVE HAGGERTY 4

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A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

TAKEAWAY

TRANSITION

IMPACT

Steve has a very conventional yet shorter backswing. We’re focused on the club movements now, but take note at how “centrated” his body is. His hips, shoulders, knees, ankles and other joints have a full range of “movement potential.”

OFF-CENTER

This is an example of a player who is “decentrated.” The body is out of alignment, which restricts his ability to produce power. Just looking at the knees is painful!

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DOWN THE LINE: STEVE HAGGERTY

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A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

BACKSWING

TOP

BEGINNING OF DOWNSWING

Here you can see the dramatic change in the club’s position. You’re seeing the changes in alpha, beta and gamma rotations. Notice how little the hands have traveled, yet the club has made dramatic changes in rotational position. As the club is being torqued, you can see how different the clubface orientation is. These are “before” pictures, and give a glimpse of one of the key places Steve and I focused our work.

TRANSITION JERK Here’s a sneak peak at a parameter we haven’t discussed in the book. It’s something you’ll hear more about in future discussions. It’s what we call “transition jerk”—the relative smoothness of the acceleration of the hub and clubhead. In transition, it’s how smooth you change the direction of the hub and clubhead from backswing to downswing

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OVERHEAD VIEW: STEVE HAGGERTY

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8

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A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

IMPACT AREA 1

IMPACT AREA 2

IMPACT AREA 3

From this view, you can really see the path of the clubhead. Steve is making an inside-out path. His mistake tended to be a block or a hook. This is one of the big benefits of 3D motion capture—the ability to move the point of reference so you can see what is happening in the swing from a variety of angles.

JACOBS 3D RENDERING

This is the same swing as shown by my software. The pink represents the clubhead, and the blue is the hub path.

When the hub makes that strange movement just after impact, that’s caused by a roll of the wrists.

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TARGET VIEW: STEVE HAGGERTY

2

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9 6

7

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A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

EARLY BACKSWING

MID-BACKSWING

TOP OF BACKSWING

Here, you can see Steve positive alpha torquing the club at the top of the swing. It’s an attempt to energize the end of the backswing, since he isn’t doing it with length. You can look at his alpha, beta and gamma torque graphs later in this chapter to compare to the visual movements.

DOWNSWING TO FOLLOW-THROUGH

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STEVE HAGGERTY

FULL SWING

Here we’re going to look at Steve’s fundamental J3D report, showing the fundamentals we’ve been talking about in this book.

BACKSWING

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

DOWNSWING TO FOLLOW-THROUGH WITH TIME STAMP

This graphic is an excellent visual to study the timing of a golf swing. Any number with a negative sign is showing the time before impact, while numbers with no sign are the amount of time after impact.

DOWNSWING

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STEVE HAGGERTY

FOLLOW-THROUGH

COMPLETE SWING SIDE VIEW

This is one of my favorite angles. Here you can see the true three-dimensional nature of the hub path.

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

DOWNSWING TO FINISH, TARGET/SIDE VIEW

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STEVE HAGGERTY

DOWNSWING TO FINISH IN QUADRANTS

Using the time stamp from page 73, the downswing is divided into four equal quadrants. Here you can separate out some of the complex movements of the hub and clubhead.

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

DOWNSWING TO FINISH IN QUADRANTS

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STEVE HAGGERTY

DOWNSWING HUB PATH WITH TIME STAMP AND SHAFTS

Now the time stamp is in relation to the hub. You can see how the hub is travelling, and where the shaft is in relation to it. This is one of the first measures I use in my analysis. It is all about the timing!

DOWNSWING HUB PATH WITH SHAFTS, TARGET/SIDE VIEW

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

CLUBHEAD NORMAL QUIVERS, DOWNSWING

The white lines (quivers) are the same length, showing direction. They point at a right angle to the path of the clubhead. If you see ridges in the movement of those lines, they show a change in direction.

HUB NORMAL QUIVERS, DOWNSWING

If you needed any proof that the hub is non-circular, here it is. Like in the previous image, the ridges in the quiver lines show change of direction.

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HUB NORMAL QUIVERS, OVERHEAD

FORCE APPLIED TO THE CLUB

STEVE HAGGERTY

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

RELATIVE SWING PLANE

RELATIVE SWING PLANE, OVERHEAD

Here you can appreciate the divergence in planes between the clubhead (pink) and hub (blue).

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STEVE HAGGERTY

PLANAR DOWNSWING TO FOLLOW-THROUGH

ROTATIONAL RESISTANCE

This shows the amount of rotational resistance during the downswing up until impact. The more resistance, the less responsive the club will be to your twisting action. A rotational resistance value of 1 means that the ‘moment’ of resistance is located at the hub. Clearly you can see that the rotational resistance is less than 1 at the start of the downswing and larger than 1 at impact. A biomechanical analysis that showed rotational resistance to be at the hub throughout the entire swing would produce VERY misleading results.

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

GAMMA TORQUE QUIVERS

HUB ILLUSTRATOR

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TORQUES

STEVE HAGGERTY

EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

FACE-ON VIEW

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

DOWN THE LINE

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

ABOVE VIEW

This is the same view we used to analyze the hub in Chapter Two.

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

OVERHEAD VIEW

The difference between this view and above? The overhead view is from straight over the player’s head. The above view is from a wall in front of the golfer, at a right angle to the center of mass of the club at impact.

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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EUROPEAN TOUR PLAYER

FORCE APPLIED TO CLUB AT IMPACT AREA

We isolated this frame to show an important element of an elite swing. The European Tour player has “forward” shaft lean at impact—something that has been talked about for 40 years in instruction. But producing that lean happens in a way you might not expect. The quivers in this image start pointing back toward the golfer—which means the player isn’t forcing the handle toward the target as much going into impact. He’s redirecting the force towards his body.

TRANSITION JERK

Compare this picture to Steve Haggerty’s. The European Tour player is doing a smoother version of what Steve is doing. The quivers coming from the clubhead are smaller for the European player, indicating he’s making a smoother transition.

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

HUB ILLUSTRATOR

You can see in the red line how the hub path curves much more as you get toward impact. In Steve Haggerty’s swing, the curve in this graph turns green near impact, revealing that his hub path is getting flatter.

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EUROPEAN TOUR PLAYER

TOTAL WORK, LINEAR WORK, ANGULAR WORK AND KINETIC ENERGY EUROPEAN TOUR PLAYER

STEVE HAGGERTY

The dominant trait for any player is linear work, the blue line. The white line is the total amount of work being produced in the downswing. If you compare it to Steve Haggerty’s (inset), Steve is contributing far less angular work early in the downswing, and trying to add a lot of it near impact.

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

FULL SWING

BACKSWING

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DOWNSWING TO FINISH WITH THE STAMP

DOWNSWING

EUROPEAN TOUR PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

FOLLOW-THROUGH

DOWNSWING TO FINISH, SIDE VIEW

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ANOTHER VIEW, DOWNSWING TO FINISH, SIDE VIEW

EUROPEAN TOUR PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

DOWNSWING TO FINISH IN QUADRANTS

Here, the downswing is divided into four equal quadrants. Then you can separate out some of the complex movements of the hub and clubhead.

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DOWNSWING TO FINISH IN QUADRANTS

EUROPEAN TOUR PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

HUB WITH TIME STAMP

HUB SIDE VIEW

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CLUBHEAD QUIVERS

HUB PATH QUIVERS

EUROPEAN TOUR PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

HUB PATH QUIVERS, OVERHEAD

FORCE APPLIED, DOWNSWING TO FOLLOW-THROUGH

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RELATIVE SWING PLANE

RELATIVE SWING PLANE, OVERHEAD VIEW

EUROPEAN TOUR PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

FLY SWATTER - PLANAR

DOWNSWING ROTATIONAL RESISTANCE

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GAMMA TORQUE QUIVERS

TORQUES

EUROPEAN TOUR PLAYER

THE WEEKEND PLAYER

FULL SWING

BACKSWING

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

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DOWNSWING WITH TIME STAMP

DOWNSWING TO IMPACT

THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

IMPACT TO FOLLOW-THROUGH

DOWNSWING TO FINISH, SIDE VIEW

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DOWNSWING TO FINISH IN QUADRANTS

THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

DOWNSWING TO FINISH IN QUADRANTS

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CLUBHEAD QUIVERS

HUB PATH QUIVERS

THE WEEKEND PLAYER

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

HUB PATH QUIVERS, OVERHEAD VIEW

FORCE APPLIED TO THE CLUB, DOWNSWING TO FOLLOW-THROUGH

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THE WEEKEND PLAYER

HUB ILLUSTRATOR

In this view, you can see lots of green—widening of the arc—in comparison to a good player’s swing.

ALPHA TORQUE QUIVERS

This player has extreme movements in his swing, which show up in the length of the quivers. The longest ones are the late, hard twisting of alpha on the club—a chicken-wing type action. You will also notice that the first half of the downswing has negative Alpha Torque as quivers point in the opposite direction.

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

DOWNSWING TO FINISH

RELATIVE SWING PLANE

The hub quivers are superimposed with the clubhead quivers. This shows how divergent the clubhead and hub planes are for this player.

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THE WEEKEND PLAYER

FORCE APPLIED

Here, I’ve superimposed an arrow on top of the player’s force graph. The grey part of the arrow is the shaft, and the red part is the direction the player’s force is being applied toward the target. In good players, that arrow starts pointing back toward the body earlier producing a greater transfer of energy.

TOTAL WORK, LINEAR WORK, ANGULAR WORK AND KINETIC ENERGY

This swing is too linear for too long, and has desperate, late angular.

A LOOK INSIDE THREE DIFFERENT GOLF SWINGS

RELATIVE SWING PLANE, OVERHEAD VIEW

CHAPTER REVIEW • One of the most productive ways to use these graphs is to compare them to the GEARS avatars of the same swings. You’ll start to see the relationship between club movements and the forces and torques causing those movements.

• Remember, the Elements shown here are just the tip of the iceberg. This book was designed to introduce you to the Science of the Golf Swing.

• The swings in this chapter were chosen for their variety. Compare and contrast the graphs of hub path shape, relative swing plane and force direction and see if you can interpret what that means for each player.

You’ll start to see how the timing of a certain movement is just as important as the movement itself.

AFTERWORD If you’ve come this far and have some questions and confusion about what you read, don’t worry. That’s completely normal. It’s taken us 150 years in the golf instruction world—and the work of some very smart people—to get to this point, so it will take a little time for everybody to fully absorb some of these concepts.

One way to immediately improve your understanding is to watch the video presentation Dr. Nesbit and I made about golf science. It brings many of the ideas in this book to life, and even touches on some things we don’t cover here. You can find it for free at my main website Jacobs3D. com, along with tons of other support materials for the video, book and Jacobs 3D software.

This is the afterword, so we’re at the end of this book. But it isn’t the end of the journey.

We’re only getting started.

The Science of the Golf Swing goes into all of the concepts we’ve discussed here in far more detail, and brings higher-level ones like alpha-beta-gamma forces, sum of the moments alpha- beta-gamma, normal, tangential and bi-normal forces, center of curvature for the hub path, club, and clubhead—plus a whole lot more. That book also covers much more about how to use the research we’ve produced. It’s been out since 2019, and is available at Amazon.

Dr. Nesbit and I have already completed some other exciting projects—like an analysis of how the putter moves during a stroke, and a complete analysis of how the various segments of the body move during the swing. We now have more information about what really happens during a swing than

at any point in the game’s history—and it will be available to anybody for the price of a book, video or lesson.

When I talk about some of the exciting things to come out of this research project, one of the loudest complaints I hear from golfers on the other side of the so-called “physics vs. art” debate is that science or “tech” is ruining players. That it is somehow robbing them of their “natural” ability, and turning them into overthinking robots.

That’s nonsense.

Find a doctor that says an MRI machine has ruined medicine and I’ll show you a doctor that doesn’t have any patients. That doesn’t mean students haven’t suffered from the application of misinformation, or from teachers that mean to use science and technology for the player’s good but apply the tools or the information incorrectly or incompletely.

I’ll say it again.

It takes understanding and study to be able to look at the data that comes from physics and apply it to the actual craft of teaching. It isn’t a substitute for teaching skill—but having the information we’ve worked so hard to find and organize sure makes the process go a lot quicker.

What do I mean by that?

Let’s go back to the MRI analogy.

Say you’re worried you might have broken your leg. You go to the doctor to get a diagnosis. Do you want to see a doctor that uses an MRI or X-ray to identify the break, so it can be efficiently and effectively treated? Or would you be satisfied if your doctor squinted his or her eyes and looked at your leg, and poked it a bit with his or her fingers?

You can find obvious breaks the second way, but the first way will be a lot more comprehensive—and it also gives the doctor something he or she can offer as a reference or proof to both you and any other doctor who is interested in seeing what’s going on.

I’m so excited to continue to share this information and improvement strategy to the golf world—and it will be a groundbreaking journey.

Like Dr. Nesbit always says: “We just let the physics tell us what is happening.”

AFTERWORD

After that, it’s our job to figure out what to do next. I’m glad you can join me on that journey.

Let me tell you a little bit about what is coming next.

We started Jacobs 3D with an analysis of how the club moves in space. Thanks to Dr. Nesbit’s groundbreaking work, we now have a full-body model of the swing. It tells us everything from the total efficiency of the swing (and where you can potentially find more energy to impart into the ball) to how the various segments of the body contribute to the greater whole—both the “when” and the “how much.” I’d say it’s like looking under the hood of a golf swing, but it’s really like being able to see inside as it goes on, in real time.

One of Dr. Nesbit’s most influential academic papers is Work and Power: Analysis of the Golf Swing. It’s where he built the first-ever model of the swing—and was the basis for the USGA’s conforming driver analysis system. That paper was released in 2005, and, in Dr. Nesbit’s words, it represented an introductory analysis compared to what we’re able to measure and study now. I’m doing an updated version of Work and Power bringing together all of the new research and study along with Dr. Nesbit’s foundational work. I’m excited for you to see it.

As always, you can find me at Jacobs3D.com, or email me directly at mj@jacobs3d.com com with any questions or comments.