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Feature
Dr Jodi Richardson
FINISHING SCHOOL! The art and science of goalkicking
A general perception in football is that despite the everincreasing focus on skills, set-shot accuracy is declining.
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HIT OR MISS: Nick Riewoldt is one of many specialist forwards to have had trouble with that finishing kick.
Inside Football
HE game has changed, that’s for sure, so in light of its increasing speed, player fatigue and modern tactical approaches to defence, can fans expect conversion rates to continue to fall? It may come as a surprise to learn that since 2000, overall set-shot kicking accuracy hasn’t actually declined much. Although the Champion Data statistics reveal a slight fall, in the past 12 years average set-shot accuracy across all teams varied between 60.2 per cent (2010) and 64.3 per cent (2000). To put this in perspective, one of the game’s greatest full forwards, Matthew Lloyd, a kicking freak with iconic preparation, recorded set-shot goalkicking accuracy of 83.3 per cent in 2006. We may consider this the outer limit of possibilities. Clearly most players don’t come close to Lloyd’s consistency and precision. Dr Kevin Ball, a lecturer in Sports Biomechanics at Victoria University and the leading authority on the biomechanics and skill acquisition of kicking in Australian football, explains that there are competing issues around goalkicking accuracy. “In the past the full forward sat close to the goal and took the predominant amount of shots,” he said. “They performed a lower volume of work and took shots closer to the goal. These days, a far greater number of players are taking shots at goal. Many of them, like the half forwards, are playing like midfielders and doing a lot of work and so are more fatigued. “These are some of the issues clouding the numbers.” In the current AFL physiological climate of high-speed running, large distances covered by all players and shorter rest intervals, players need a certain volume of kicking practice each week to maintain their accuracy under fatigued conditions. However, Dr Ball has found that the amount of kicking practice in most clubs is low. From a training point of view clubs are managing a big range of loads including fitness, strength, skills and strategic workloads and fitting in the necessary volume of kicking is becoming increasingly difficult. Dr Ball’s experience with kicking in the AFL is second to none. As the Australian Institute of Sport’s AFL kicking coach, consultant to a number of AFL and NRL clubs and a member of the AFL kicking skill acquisition group, he knows just about all there is to know about kicking technique. He stresses that good technique is essenX coaching of kicking tial and that improved Summer Special, 2011-12
skills is important in amateur levels of football so that players are better prepared coming into the AFL. “The AFL is working hard to develop coaching skills down the ranks; coaches should keep an eye on the AFL website for resources that are in production. It’s important for coaches to know what to teach and how to teach it,” Dr Ball says. The AFL has also endorsed a company called Draftstar to develop and deliver skills programs to junior and senior players. Dr Ball says the basics of good technique include a good ball drop, the more consistent the better; upright posture, balance, a strong support leg, straight follow-through with the kicking leg and maintaining a strong kicking foot so that the player’s ankle remains rigid throughout the kick. If the player has a weak or “floppy” kicking foot, they absorb a lot of the force of the kick, reducing the power and distance of the kick. This often changes the direction of the kick in the process. Boot contact on the ball should be with the laces. Dr Ball says the set shot is a self-paced skill where players have time to think. Traditional (explicit) coaching practices where a player is verbally told what to do can result in a player overthinking his setshot, a skill which should essentially automatic or “unconscious” in its execution. Research shows that the use of implicit coaching techniques, where the skill is taught using analogies, metaphors and related drills, is the best approach for selfpaced skills, especially those performed in stressful situations. Effective mental preparation for set-shot goalkicking goes hand in hand with good technique. It’s not enough on its own, but together these attributes can be the difference between good and excellent kicking accuracy. “A useful technique that most AFL clubs use is developing set-shot kicking routines with their players,” Dr Ball said. “The routine begins with the mark and ends with the kick and can be very individual for players. “Some players like to move in quickly for the kick, others like to take some time to compose themselves. “Some players use a physical trigger such as pulling up their socks or looking at the ball. Matthew Lloyd famously threw grass in the air before each set shot; this was all a part of his mental preparation.” Visualisation is another important aspect of mental preparation recommended by Dr Ball. In its simplest form, it involves picturing in your mind the kick and the ball going through the goal before you
Inside the game 11
PRESSURE KICK: Does the likelihood of this Jack Riewoldt kick scoring a goal depend partly on how much his team needs it?
begin the physical part of the skill. Dr Ball determined in his research that the maximum distance a player can kick is a consideration when it comes to accuracy. His unpublished results show that shots from up to 85 per cent of maximum kicking distance are more accurate than kicks beyond this fraction. Players need to understand their capabilities and make a decision about attempting a set shot at goal or finding a player in a better position. A mathematics journal might seem a strange place to get some insight into set-shot kicking but nonetheless, a recent article by Peter Galbraith (University of Queensland) and Terry Lockwood (Marian College) has advanced the science of set-shot kicking and refuted some perceptions about difficult kicking positions. The title of the article is “Things may not always be as they seem: the set shot in AFL football”. It demonstrates that a kick from 45 metres directly in front of goal is equivalent in difficulty to a kick at a 45-degree angle from the posts at 32 metres, and a kick on an 18-degree angle from 20 metres. The two latter positions would be a preferable kicking position for a player without a long distance kick. The authors comment that “there seems to be one perception that is common to almost everyone and this is that the central corridor from goal to goal is the most favourable place to be when kicking for goal”. “When kicking from directly in front of the goal from a distance of 50 metres, despite the appearance of generosity, the actual angle which is available to the kicker is only a touch above seven degrees. “We have found in our analysis that there are many positions, some at quite substantial angles, that afford better opportunities.” The authors suggest players use finger widths at a constant distance from their
BELOW: The master finisher, Matthew Lloyd.
‘A school of thought is that left footers have the potential to be better kicks.’ face to measure the “daylight” between the goalposts in the distance. Lockwood says that players can often think a set shot is tougher than it may actually be and that this technique could give players confidence that they have the ability to kick the goal from what they may have considered to be a tough angle. Some players, like Geelong’s Steven Johnson, kick around their bodies to open up the face of the goals at sharp angles. Psychology can’t be overlooked as an influence on kicking accuracy either, particularly as this dynamic changes at different times during games. In his blog at www.understandfooty. com, Michael Ellis, sub-editor of this magazine, has written a thought provoking piece on “How to fix the yips”. He says: “As one wise old AFL coach once observed, you don’t kick goals with your boot, you kick them with your head. “The pressure of expectation gets to many forwards and makes them tighten up in the execution of the skill.” His premise, applying a psychological principle known as loss aversion, is that in any sport, when anticipating a gain (i.e. a goal) players automatically become more conservative and tighten up physically, instead of remaining relaxed, fluid and positive in their action (like deadeye former Hawk Mark Williams). Ellis argues that the likelihood of a set kick going straight depends partly on the state of the game and the kick’s importance to the result. “Have you ever noticed how often a
player in a trailing team that desperately needs a goal actually nails the shot? I’d like to see the stats on that because my observation is that those ‘must kick’ goals tend to be kicked,” he said. “The harder kick is the one that seals the game, because the mindset then is more about gain anticipation. Then the player more easily ‘chokes’. “Players with the goalkicking ‘yips’ especially need to focus on something other than the outcome of their kick.” Dr Ball uses a range of technologies to conduct performance analysis as a kicking specialist with the view to modifying player techniques more quickly than would be possible without the use of these technologies. “We use force plates to measure the stability of the support leg during the kicking action, high speed kinematics where we attach markers to the body and video the player kicking to produce a three-dimensional model of the player performing the skill, high-speed video so we can examine each kick in super slow motion and ‘intelligent leggings’ that can provide knee angle data,” he said. The smart fabrics are a fascinating technological development that Dr Ball uses in his work with the AISAFL Academy players while in camp in Canberra with Dr Elissa Phillips and Professor Damian Farrow. Dr Richard Helmer, research engineer Inside Football
at the CSIRO, developed the “intelligent leggings” which are prepared by mounting textile strain sensors across the knee on a pair of leggings commonly worn in sports training. The strain sensors are similar to “conductive fishing line” that moves within the knitted structure of the leggings during the bending and straightening of the knee joint. The leggings provide information about the angle of the knee during certain stages of a kick. Dr Ball is interested to know how bent the knee is early in the kick, the time taken to make contact with the ball, and knee angle at ball contact. The contact of the ball on the foot is detected by placing electrodes on the foot and an electrically conductive region on the ball that completes a cir-
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cuit when contact is made. This allows the researchers to know the exact moment of impact. If there is less time from the start of the kick to ball contact, the kick must be faster, which means more power can be developed. If the time to ball contact is considered slow, then Dr Ball can make the relevant adjustments to the player’s kick immediately. Power and accuracy are both important so with the information provided by the technology, Dr Ball can instruct players about how their execution of the kick should be modified. Does it make a difference which foot you kick with? Dr Ball reports that no statistical difference has been found between right and left footers for accuracy but that there is a school of thought that left footers have the potential to be better kicks. “The left side of the body is controlled by the right side of the brain and the right-hand side of the brain controls spatial awareness, which is knowing where your body, arms and legs are in space. In elite sport, research has shown that left footers are more able to control their feet,” Dr Ball says. The introduction of the Buckley kicking test into the draft camp in 2009 highlights the importance placed on kicking accuracy in the AFL, a message that should be heard by aspiring juniors. Assessing ball speed, spin, accuracy and trajectory, the test can be set up and practised at any level of football to develop a player’s decision making and kicking accuracy. The diversity of the range of disciplines seeking to understand and improve setshot kicking accuracy in the AFL is astounding, making AFL sports science genuinely multi-disciplinary.