An Investigation into Golf Ball Speed at Hole Entry: Sheppard et al 2016
An Investigation into Golf Ball Speed at Hole Entry Should golfers be more concerned with finishing a certain distance past the hole or optimising the effective size of the hole to give them the best chance of holing a putt?
Jonathon, J, Sheppard., Paul, D, Hurrion., & Andrew, R, Collinson. Presented at the 2016 World Scientific Congress of Golf St Andrews, Scotland, July 2016
Ball Speed has a significant effect on putting results and should be considered an important factor when putting at any level (Pelz, 2000). Despite this, the ability to control the speed of the ball can often be overlooked which is surprising considering approximately 40% of all shots played on the PGA tour are putts. Cochran & Stobbs (2005) describe four reasons as to why a putt might miss. 1) 2) 3) 4)
Assessment of line/perceived break Failure to set ball off on correct line Failure to set ball off on the correct speed Random irregularities in speed
“Speed is more important than target line when on a slope” (Dewhurst, 2015) The errors in direction and speed can be illustrated in Figure 1. The plot on the left of this figure shows the effect of errors in selecting the correct start direction of the putt. The required break for this putt is calculated to be 37 inches to the right (dotted line). The two missed putts were started with breaks of 18 inches and 56 inches, respectively. Despite a major misread, (50% of the estimated break), the ball finished less than 3 feet from the hole. In contrast, the plot on the right are the effect of errors relating to initial changes in ball speed (Please note: All three putts started on the same line) A ±10% error in ‘Ball Speed’ from the intended speed of 7.2 mph required to hole the putt, resulted in the slower speed (6.48mph) finishing 3 feet short, whilst the fastest (7.92 mph) left a 6 foot return putt! And this is only a stimp reading of 7…
An Investigation into Golf Ball Speed at Hole Entry: Sheppard et al 2016
Figure 1 : The effects of Âą 50 percent errors in the initial trajectory (left) compared to the effects of only Âą 10 percent errors in the putt speed (right).
Aimpoint (2013) & Pelz, (2000) identified that the optimum speed of a putt should finish 9 inches and 17 respectively, inches past the hole. However, a common distance referred to by professional golfers is 1 foot or 30 cm past (PGA Teaching Manual, 1990). See Figure 2. However, this distance may be personal to the golfer, or does it even change depending on distance to the hole, along with slope & stimp and even the state of play of the game? Is there a difference in speed with a Par, Birdie or even a Bogey putt?
An Investigation into Golf Ball Speed at Hole Entry: Sheppard et al 2016
Figure 2 : Distance past the hole
The aim of this study was to investigate the effect of a 3° slope on ball kinematics. The primary objective was to identify differences in the speed of putts that finished 0.30 m past the hole and to determine any effect that this might have on the effective size of the hole. When a ball approaches the hole at a high speed, the likelihood of a successful putt reduces. This can be due to the increased chance of either a “lip out” or the ball might roll straight over the hole.
Method Twelve positions were located equally around a ghost / fake hole in a clock face orientation (Figure 3). All putts were completed using a Perfect Putter (The Perfect Putter, USA), had to pass through the centre of the hole and stop on a ring marked 0.30 m from the circumference of the hole. The balls velocity, the distance it travelled and time taken were measured at five locations along the balls trajectory (0.40 m prior to the front of the hole to 0.30 m after the back of the hole) were used for comparison purposes. The protocol was repeated on two different surfaces, a Huxley putting green (Stimp 10) and a indoor putting carpet (Stimp 10.5), on a slope of 3°. A Quintic High Speed camera set at 200fps (resolution 850 x 600 pixels) recorded each putt. Videos were automatically digitised using Quintic Biomechanics v26 to find the centre of the ball. Absolute X and Y co-ordinates were exported to excel for further analysis.
An Investigation into Golf Ball Speed at Hole Entry: Sheppard et al 2016
Figure 3 : Experimental Design – Clock face
Analysis/Results Finding showed that when putting directly up the slope from 6 o’clock, the average velocity at the front of the hole was 0.66 m/s ± 0.01 (Huxley) and 0.71 m/s ± 0.02 (Putting carpet). However, when putting directly down the slope, 12 o’clock, the average velocity was 0.29 m/s ± 0.03 and 0.25 m/s ± 0.03 respectively. Putts directly down the slope were over two times slower at the front of the hole compared to those directly uphill for both surfaces (Table 1). This equates to differences of 127% (Huxley) and 184% (Putting carpet). Distance travelled to reach the line 0.30 m after the hole was on average 0.04 m greater when from the 4 and 8 o’clock positions (0.36 m ± 0.03) as opposed to the 12 and 6 o’clock positions (0.32 m ± 0.04). This was due to the curvature of the path of the balls putt.
An Investigation into Golf Ball Speed at Hole Entry: Sheppard et al 2016
Figure 4 : Ball Tracking 5 measurement locations along the balls trajectory and all 12 clock face average trajectories overlaid for comparisons.
Table 1 : Velocity measures at each measurement point for 6 O’ Clock and 12 O’ Clock positions.
An Investigation into Golf Ball Speed at Hole Entry: Sheppard et al 2016
Figure 5 : Velocity measures at each measurement point for both surfaces.
Figure 6 : Distance travelled past the hole for each position.
An Investigation into Golf Ball Speed at Hole Entry: Sheppard et al 2016
Conclusions The findings from this study help to highlight the importance of ball speed when putting. Ball velocity was consistently less than the velocity required to fall in at the front of the hole, v < 1.31 m/s (Holmes, 1991). However, the speed of the ball can also have an impact upon the effective size of the hole. For example, when putting directly up the slope, at 0.65 m/s, the effective size was reduced by approximately 25% (Wesson, 2008 & Holmes, 1991; Figure 8). Whereas putting directly down the slope, at 0.23 m/s, resulted in an approximate decrease of only 4%. Similarly, if a downhill putt travelling 0.65 m/s missed the front of the hole, then this could leave an uphill putt of over 4 ft. This brings implications to players of all abilities and probes the question should golfers be more concerned with finishing a certain distance past the hole or optimising the effective size of the hole to give them the best chance of putting?
Table 2: Effective Size of the Hole.
Figure 7 : Effective Size of the Hole.
An Investigation into Golf Ball Speed at Hole Entry: Sheppard et al 2016
Figure 8 : Holmes (1991) and Wesson (2008) representations of how the effective hole size changes relative to ball speed. The highest and lowest marked velocities at the front of the hole marked from the current study.
Summary * Ball speed is a key component in order to putt successfully. * Putts directly down the slope (6 O’Clock) were over TWO AND A HALF TIMES slower at the FRONT of the hole compared to those directly uphill, a difference of 157% to finish 1 foot past the hole. * Aiming to leave the ball 1 foot past the hole has a MARKED effect on the effective hole size, particularly when putting on a slope. * Entry speed needs to be specific to distance, slope & stimp and may also vary depending on a person’s preference, along with the state of play of game / match. “In reality, it is harder to control speed than line. If you can’t control speed, how do you know which line to choose” * This brings implications to players of all abilities and probes the question should golfers be more concerned with finishing a certain distance past the hole or optimising the effective size of the hole to give them the best chance of holing the putt? References: Cochran, A. J. & Stobbs, J. (2005). Search for the Perfect Swing. Chicago: Triumph Books. Dewhurst, P. (2015). The Science of the Perfect Swing. Oxford: Oxford University Press. Donaldson, J. (2013, March). Green Reading: Need for correct speed. Aimpoint Golf. Hurrion, P. (2012, July). Golf International 111: A Rolling Brief Holmes, B. (1990). Putting: How golf ball and hole interact. American Journal of Physics, 59, 129-136. Pelz, D. (2000). Dave Pelz's Putting Bible: The Complete Guide to Mastering the Green. New York: Doubleday. Riddoch, C. (2013). Expert Putting: The Science Behind the Stroke. Printed by CreateSpace. Wesson, J. (2008). The Science of Golf. Oxford: Oxford University Press. Witt, J. K., Linkenauger, S. A., Bakdash, J. Z., & Proffitt, D. R. (2008). Putting to a bigger hole: Golf performance relates to perceived size. Psychonomic Bulletin & Review, 15, 581-585. Wiren, G. (1990). PGA Teaching Manual: The Art and Science of Golf Instruction. Florida: PGA of America
Presented at the World Scientific Congress of Golf VII July 18-22 2016 : St Andrews, Scotland, UK. Speed Changes Everything – an investigation into the effect of launch characteristics on putting performance Dr Paul, D, Hurrion., James, MacKay., Mark, Sweeney., Mr Andrew, R, Collinson Purpose A putt hit with the perfect line and initial start speed might still miss the hole due to varying amounts of skid, roll and launch angle. The following study investigated the variation of launch characteristics during putting to determine how these differences affect the outcome of ball speed. Speed has a significant effect on putting results and should be considered an important factor when putting at any level (Pelz, 2000). Despite this, the ability to control ball speed can often be overlooked and focus in coaching and performance predominantly aims to control the speed of the putter head. Aim and green reading are the primary determinant of putting direction consistency (Karlsen et al. 2008), however little or no focus is aimed towards ‘clubhead twist’, centre contact or even the launch characteristics of the golf ball. The purpose of the study was to better understand a player’s ability to control ball speed and distance control, despite their normal variability in putter head speed by changing launch and spin conditions.
Method The Quintic Ball Roll system uses a high speed camera (360fps) to measure a variety of factors including ball speed, roll, spin, launch and skid during the first 16 inches of a putt. Ten putts were performed by an elite professional (Top 60 World golf Rankings – Sept 2015) outside on a flat green (0% slope; Stimp 11). The putt distance was 12ft and each putt was recorded individually using the Quintic Ball Roll system. Speed control of the participant was paramount, therefore the participant selected is widely considered to be one of the best ‘pace putters’ in the world. The data collected by Quintic Ball Roll was mathematically modelled using AimPoint software, a green reading tool that helps to understand break speed and aim by assuming true roll over the entire length of the putt. All 10 putts were simulated across different angles (12 angles around the clock face over 30 degree increments) and three different slope percentages (1%, 2% and 3%) to determine the outcome of the ball. The modelling used a surface stimping at 11.
Analysis/Results Table 1 shows the raw data collected for each of the ten putts on the flat surface. The range in ball speed at 0 inches was 0.28 mph (5% variance from the mean) and this increased to 0.41 mph at 16 inches (14% variance from the mean). Due to differences in launch angle, roll and skid, this equates to a further difference of 0.56 mph between the fastest and the slowest putt by the time the golf ball reached true roll (zero skid). AimPoint software was used to quantify exactly how much a range of 0.41 mph might change the outcome of a putt given the same start direction. Figure 1 highlights the results of what percentage of putts would still go in the hole, based on the gradient and angle. The red lines indicate a miss, blue indicate holed and black is the average putt line. When putting using the 3% slope, 60 degree down, there was over a 3ft variation in the finishing distance between the fastest and slowest putt.
Conclusions The results clearly show that as the slope gets steeper the variance in launch characteristics accentuates the variance in ball speed, causing the ball to slow down at difference rates. The participant tested had world-class speed control with only a 0.24 mph variance across 10 putts, however a greater variance will accentuate this even more. The results also showed that smaller uphill angles are more forgiving of speed variances than cross-hill or downhill angles. From a strategic perspective, it should be obvious where the ideal position to putt from is and from a performance perspective it is important to understand that having consistent launch conditions can have a big effect on distance control. Despite this, some natural variance in speed must be expected (golf is an outdoor sport), and when facing a steep fast downhill putt, it is dramatically harder to make than the equivalent uphill putt (Wesson, 2008 & Holmes, 1991). This brings implications to players of all abilities and probes the question should golfers be more concerned with finishing a certain distance past the hole or optimising the effective size of the hole to give them the best chance of putting.
Putting is a game of percentages - be sure you know where the odds lay in your favour. Given that the golf ball can lose up to 30% of its initial speed before it gets to true roll, identifying this point is clearly important for a player to be consistent on the putting green. From a coaching
perspective, a player needs to be able to consistently control ball speed, along with launch, spin and roll values in order to achieve a consistent end distance. A consistent strike point is also required for this to occur. The authors would also stress, that the golfer in question is inside the top 60 in the world ranking (September 2015) and in their experience don't believe a human can be much more consistent with ball speed immediately after impact.
“Most three putts aren’t caused by bad green reading, but by bad judgement of speed” Ben D. Crenshaw
References Pelz, D. (2000). Dave Pelz's Putting Bible: The Complete Guide to Mastering the Green. New York: Doubleday. Karlsen, J., Smith, G, Nilsson, J (2008). The stroke has only a minor influence on direction consistency in golf putting among elite players. Journal of Sports Science, February 1 st 2008; 26(3): 243-250 Holmes, B. W. (1991). Putting: How a golf ball and hole interact. American Journal of Physics, 59, 129-136. Wesson, J. (2008). The Science of Golf. Oxford: Oxford University Press.
POSTURE IS THE KEY TO PUTTING
improve your game
LIPSTICK DRILL
PAUL HURR ION
62
INCONS I STENCY in the strike area may seem a small hiccup, but it can afflict any golfer, even Major champions. It can either defeat your aim of being a better putter – or be overcome quickly if you use my simple answer. Firstly – yes! It matters. Every time you miss the ‘sweet spot’, the impact twists the putter slightly. This means miss-hits producing misdirected putts and poor strikes leading to short putts. To be a good putter, you have to create a good repeating stroke that enables consistency of strike. Striking the ball out of the ‘sweet spot’ every time not only gives you the best roll, but also the best feel. Importantly, the consistency builds your confidence … plus there is a hidden bonus. And now my simple answer: The Lipstick Drill. I guarantee it can help you to improve distance control, direction and confidence overnight. And the hidden bonus? Focusing on striking the ball in the centre of the putter will help prevent your eyes following the ball too soon and add another stability factor to your putting style.
MARCH 2010
The Lipstick Drill
AS I A N G O LF M ON THL Y
Do you consistently strike the ball from the same part of the putter face? And is that the centre or ‘sweet spot’ of your putter? Actu ally, do you know where you strike the ball on the putter face? Does it matter? Asian Golf Monthly putting guru Paul Hurrion says ‘yes!’
The purpose of this drill is to check if you are striking the ball on the centre of the clubface. Smear lipstick on the face of the putter. Then hit a putt. The mark in the lipstick will show you where the ball is being struck. Is the strike where you thought it was? Is it in the centre? Repeat the drill 10 times and look for the ‘consistency’ of the pattern that you have created. More three-putts are caused by pace control than poor alignment, so in order to control the pace of the golf ball, it is vital that the ball must come consistently out of the sweet spot of the putter face. Importantly, this drill
“MO RE THREE -PUTTS ARE CAUSED BY PACE CON TR OL THA N POO R AL IGNME NT.” does not interfere with the putter face or deaden the feel of the hands. If your putts are inconsistent in terms of strike (heel and toe), try switching to a putter with a higher Moment of Inertia (MOI). This will help give you greater sta bility or forgiveness with off-centre hits and cut misdirection and distance control errors. Working with GEL Golf, I have de signed the Paul Hurrion Signature Range of putters to help golfers enjoy the key benefits Tour players look for on the
greens. The groove and multi-layer aluminium insert technology enables weight to be positioned around the perimeter of the putter head, creating a high MOI for the precise reason that not even Tour players strike the ball out of the centre every time. Based on the bio-mechanical principles I have studied, I know that consistent strike and putters with a high MOI help you to create stability and consistency at the point of impact in the area of the game that matters most – your putting.
Dr Paul Hurrion is among the world’s foremost putting coaches. His passion for golf has led to a specialism in putting analysis and advice, assisting European Tour professionals and holding PGA accredited Putting Clinics. Through his work with Padraig Harrington, he advised Hi-Tec on the bio-mechanical design dynamics of their new CDT Golf Shoe. For further information, visit http://www.quintic.com/quintic_putting_laboratory.htm or www.paulhurrion.com Paul has recently designed a signature range of putters for GEL Golf. For further details on the GEL Putting Alignment Mirror, visit
www.gelgolf.com
DON’T STRANGLE THE PUTTER
improve your game
60
Asian Golf Monthly putting guru Paul Hurrion suggests a drill that will enable you to discover the correct grip pressure you require when putting. through the ball’. The key is to let the ball get in the way of the putter. Don’t hit at it! The only connection you have with the putter is via the grip … and how much grip pressure you exert onto the handle can significantly alter the energy trans ferred from the body into the club head.
PAUL HURR ION
THE MAIN FOCUS when playing on fast greens is to ensure you do all you can to take the ‘hit’ out of the stroke. The key to putting on fast greens is pace control. Pace control is the result of energy transfer from the body into the club. It is important to remember to ‘swing
Constant ‘grip pressure’ for me is the key ingredient into consistent distance control with your putting stroke. The image here was taken at Quintic indoor putting laboratory, which serves as an excellent practice facility for pace control.
Avoid Muscular ‘Gridlock’ If you can see the whites of the knuckles when you take your grip, you’re already in trouble. Too much pressure in the hands reduces the feel in the forearms and shoulders; you end up with a muscular ‘gridlock’. Here’s a simple, yet very effective, drill I use to ensure you always have the correct grip pressure during your stroke. Hold the club out in front of you horizontally using you normal grip (pictured); Slowly relax the grip pressure in both hands until the toe of the club starts to drop slightly (no more than one centimetre), as I am doing in the picture; At the moment the putter-head begins to fall, you have found your ideal grip pressure; Once you have that sensation, take your putting posture. My guess is that your grip pressure is now lighter on the club than it is when you are getting ready to make a putt. It should be. This lighter, more sensitive pressure will ensure that both hands work together as one unit during the stroke; In the majority of cases (for right-handers), the right hand is the dominant hand with the putting stroke. That can lead to trouble and inconsistency. For a balanced and repeating stroke, they must work together.
Conclusion
ASIAN GOLF MONTHLY
FEBRUARY 2010
To establish the correct grip pressure, hold your putter out at arm’s length and simply relax your hands until the putter-head begins to fall. At that moment you have found your ideal grip pressure. A light, sensitive grip will allow your hands to work together in balance. Squeeze the life out of your grip and you effectively squeeze the feel and rhythm out of your stroke. Dr Paul Hurrion is among the world’s foremost putting coaches. His passion for golf has led to a specialism in putting analysis and advice, assisting European Tour professionals and holding P GA accredited Putting Clinics. Through his work with Padraig Harrington, he advised Hi-Tec on the bio-mechanical design dynamics of their new CD T Golf Shoe. For further information, visit http://www.quintic.com/quintic_putting_laboratory.htm or www.paulhurrion.com Paul has recently designed a signature range of putters for
GEL Golf. For further details on the GEL Putting Alignment Mirror, visit www.gelgolf.com
6 LEARN WHAT STRAIGHT IS
PAUL HURRION