How to use your eyes to improve your free-throw shooting Performance

Introduction & Method

In previous articles on sports vision and neurocognitive training, I address not only the key role visual perception and processing plays in sports but also how this can be assessed, trained and even predict performance in visually demanding sport such as ice-hockey. I know shift gears to basketball but to a more static sporting task, the free-throw.

Enjoy the read and please feel free to comment!

A classic paper Harle and Vickers (2001) investigated how athletes used their eyes during the free-throw shooting action. The researchers wanted to see if a relationship existed between visual fixation in pre-shot routine, during and after the shot, and free-throws made. Earlier research suggested that difference in visual control exist between high and low free-throw made percentage (FTM%) shooters. Expert shooters were found to fixate earlier at the target during the preparation of the shot and was maintained prior to the execution of the shot. Even more, the final fixation was held for almost a second. This last fixation was termed “Quiet Eye (QE) moment. Years later, this concept has also been observed in highly skilled individuals across many different sports (golf, dart,volleyball, soccer)

The researchers recruited three collegiate female basketball teams. Team A was initially recruited for this study and was followed over the course of two seasons whereas Team B and Team C were recruited based on their final-four placement the following two seasons. Team B and Team C would serve as controls. Team A athlete`s visual and motor behavior was assesses using a head-mounted visual system (eyetracker) and external cameras. This clip with former actor Alan Alda demonstrates the use of this technology and how parts of this study was conducted.

Gaze characteristics and FTM were recorded prior to season 1 and post-tests was completed six months later at the conclusion of the season. The shooting test-protocol comprised of 4 series of 10 shots, where the last 3 sets were completed while wearing the eye-tracker. Team A athletes then received extensive feedback on their overall shooting performance, as well as being compared to an expert shooter who displayed the QE characteristics.

QE was utilized as an objective measure of location, onset, offset and duration of gaze. This was recorded while participants performed a motor skill. Onset is referred to as when tracking or fixation on a specific target was made. This process occurs before shooting action (movement time) is initiated. More specifically, for a given motor task, the QE is defined as the final fixation or tracking gaze on a specific location or object within an area of 3° of central vision for a minimum of 100ms. Subsequently, the offset of QE is defined when gaze location deviates from the central vision area for 100ms or longer.

Team A athletes received quiet training through a specific routine which I will briefly explain in three steps:

I. Take your stance – direct your gaze to the hoop, bounce the ball three times and repeating the phrase “nothing but net”

II. Hold ball in your shooting stance – maintain QE and focus on fixation point for at-least 1.5 seconds while you saying the words “sight-focus”.

III. Shoot quickly using a natural and fluid motion – where the ball trajectory goes through the center of your visual field, occluding or hiding the target you were fixating on. There is no need to maintain the gaze on the hoop as you shoot.

This concept was reinforced during practices in team and individual format through-out the two seasons the intervention lasted.

The researchers expected that Team A athletes would achieve significant improvement pre-post in QE location, QE onset and QE duration. This is turn was thought to contribute to a significant improvement in accuracy (FTM%) in testing environment as well in competitive setting. Additionally, The researchers expected Team A to be significantly more accurate than Team B and C over the two season in FTM% and in transfer effect (season 1, season 2), where Team A`s FTM% in games was compared to that of Team B and Team C.

Findings

The current study analyzed 5 possible fixation locations; backboard, back rim, left rim, right rim and front rim. The great change post-training in allocation of QE was for front rim (from 23-57% pre-post) and greatest reduction in QE allocation was found for the backboard (32%-4% pre-post).

Team A athletes even increased their QE duration from mean value of 783ms to 981ms. More importantly, a significant interaction was found between shots made and this final fixation duration.

Prior to season 1, Team A`s free-throw efficiency was roughly 62%. By the end of the season, this had increased to 74%. However, in-game FTM% was 54% that year, compared to Team B and Team C who put up 67.67% and 61.36%, respectively. Come season 2, Team A made an impressive improvement for in-game FTM% to 76.66% (+22.6%), where Team B and Team C put up 66.18% and 74.05% from the free throw line.

The researchers broke down the shooting-sequence into two phases, prep-down and movement-time shot (MT-shot). The former can be described as the ball bouncing, wording and QE moment, or the first two steps in the 3-step QE routine. The MT-shot was referred to as the time-period between beginning and completion of the shooting action. The prep-down time increased from 63%-68% while and the MT-shot decreased from 32%-37% of the total shooting sequence time.

Discussion

As previously mentioned, Team B and Team C were selected at the conclusion of season 2. Team B happened to be the national champions in season 1 and Team C came in 2nd. Team A did not make it to final-eight play that season. In season 2, Team C took were crowned champions, Team A came in 2nd and Team B fell to 4th place.

Small improvements in many areas can lead to significant gain. Let`s first discuss FTM% in game and training. The researchers also surveyed practice routines from Team B and Team C. All participating teams were asked to estimate how many free-throw shots they made per athlete per week. Team A reported 5 shots per week, Team B reported 26 and Team C reported 40. The number of free-throws made by athletes on their own ranged from 100 per week for Team A and Team B, and 300 for Team C. This finding may suggest the benefit of deliberate practice, which has been proposed as one of the key factors in developing expertise. The implementation of the QE routine into the free-throw shooting may have led to a greater attention, concentration and likely also retention of skill. In return, increasing overall quality and performance both in practice and in game.

A surprising finding in the study was that the pre-shooting routine (prep-down) was found to be 5% longer and the actual shooting sequence was 5% shorter (MT-shot). This may relate to the fact that the overall three-throw action became more efficient with a quick and smooth execution. Team A displayed a greater stability of QE but also relative more time was allocated to the preparation of the shot and less to the actual shooting action.

The QE phenomenon has 5 characteristics: location, onset, duration, offset and timing. The leading researcher on QE Joan Vickers, suggested timing of QE relative to shooting action in this context appear to be the most important characteristic. Previous research has looked at free-throw shooting technique and performance and compared it between practice and game. It was revealed that players took longer time to prepare for a shot in game as compared to practice. This inconsistency tended to lead to less accuracy in games. The pre-shot routine has been utilized to visualize the end-performance and also viewed as a mind- clearing process which can enhance the efficiency of the task. The researcher in this study also observed a change in shooting-mechanics after QE protocol was implemented. This was a pleasant side-effect from the changes associated with more time allocated to the preparation of the shot and less to the shooting motion. Until that point, no other study have provide objective information about how the visual gaze can affect shooting accuracy and possibly also shooting mechanics.

Another intriguing observation was that the gaze was not fixated on the target through-out the shooting action. Authors termed this for “suppression phase”. As already mentioned, QE period occurs and remains stable approximately one second before the shooting action begins. This was termed “location phase”. The sequence of the two events has been termed as location-suppression. During the location phase, neural and cognitive mechanisms are processing the visual information prior to the final aiming movement. The suppression phase begins immediately after the QE and is initiated during the aiming movement when the ball occupies the visual field of the hoop. Here, visual perception is suppressed in order to avoid additional information that could disturb the on-going processing of visual input obtained during the location phase. This may be unique to sports like basketball and dart where final task movement is occluded. Other aiming tasks such as rifle shooting and billiards does not display this feature.

Moving on to a more dynamic and demanding visual-motor task in basketball, how does the QE explain athletes who pull-off contested and all-impressive catch-and-shoot?  We first have to address how learning takes place and how it may be recalled or reproduced. It is beyond the scope of this article to go through all the areas and factors associated with learning and long-term memory. Skill development goes first through explicit learning, where we learn the “what” and “how” of the skill. We all know that getting good at complex skills takes time and when we arrive at mastery level it becomes automated, procedural or what sports commentators wrongly term “muscle memory”. If we consider what governs all our movements, we should also say muscles don’t have memory but the brain or motor system stores similar movements that achieve same outcome. A more suitable term would then be “motor memory”. This is a more economical state in which there is a shortcut in processing which allows for rapid decision making and execution. According to the definition, the QE phenomenon can still be present in the context of contested shots with significant time constraint. The athlete, the ball, opponents and team-players are all moving providing a substantial increase in visual input. Expert athletes have been shown to efficiently use central (foveal) and peripheral (para-foveal) vision simultaneously which helps them pick up relevant information to anticipate how the situation may unfold. Yes, similar to the analytics and AI we see in sports and business alike, the brain is also gathering and processing large chunks of data to predict future events. The brain is already doing this to the point where we do not have to think about it and then decide and execute a motor action in a fraction of a second. Some athletes may be very receptive to training and subsequent adaptation in these areas and are very likely the same one`s we pay to watch every night. Therefore, when we see basketball players do the feat of catch-and-shoot on weekly basis, we can argue it is the convergence of recall of long term skill (motor memory now, ok!), optimal visual attention (QE) and thirdly, athleticism.

Transitioning back to the article, the 5 characteristics of QE were only observed in practice and therefore transfer effect to game performance can only be speculated as research needs to be conducted in the specific environment. Also, comparison with Team B and Team C would have been of interest. Similar research done in professional setting would be of great interest. Although substantial technological improvements have occurred since the study was conducted, league rules and the CBA may potentially put a roadblock on allowing athletes wearing eye-trackers in the name of research in the future.

 In the figure below you see statistics over free-throw made in professional setting. In season 2 Team A averaged 76.66%, which was at the time 1.8% and 2.8% higher than the NBA and WNBA average, respectively. Beside the substantial improvement made, keep in mind this was college athletes where free-throws made prior to the study wasn’t much to brag about. However, I firmly believe that any athlete at any level will benefit from this method not only for improving their free-throw numbers but also as it applies to other skills on the court, passing and 3-point shot to name a few.

 Season WNBA (FTM%) NBA (FTM%)

2018-2019 E.D Donne (97.7%)   Malcolm Brogdon (92.76%)

2017-2018 Diana Taurasi (92.4%) Stephen Curry (92.05%)

2016-2017 E.D Donne (95.3%) CJ McCollum (91.16%)

All-time high (career) E.D Donne (93.4%) Stephen Curry (90.5%); Steve Nash (90.4%)

Source: Basketball-reference.com

ESPN.com

Practical Application

The main take-away from the article would be to implement the three-step QE protocol to those athletes who are willing to try. The authors noted that compliance was high with Team A and reason may be the fact that it didn’t directly affect their shooting technique. In short, QE can:

1.     Help shooter settle down and not rush the preparation

2.     Leads athlete`s attention to the fixation target and less on shooting action. 

3.     What you do in practice is how you do it in competition, leaving less room for distractions.

 In conclusion, this research was among the earliest reports on QE phenomenon in basketball athletes. If an athlete has the best statistic in the world in a given task, they may possess what Joan Vickers calls “hot hands” where QE may be the main factor.

Some athletes may not possess physically dominant attributes as others in their sport. Stephen Curry is a good example of that and has already achieved legendary status for his shooting ability. Speaking of legends, I`ll end with a quote of what another graceful athlete said about what made him so successful:

“I couldn’t beat people with my strength; I don’t have a hard shot; I’m not the quickest skater in the league. My eyes and my mind have to do most of the work”

Wayne Gretzky

In the next article, I will follow the same thread and how NBA players use their eyes in shooting performance.

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Reference

Harle, S. K., & Vickers, J. N (2001). Training Quiet Eye improves accuracy in basketball free-throw. The Sports Psychologist 15, 289-305.

Piras, A., Milena, R., Lanzoni, I. M., Persiani, M., and Squatrito. (2015) Microsaccades and prediction of a motor act outvome ina dynamic sport situation. Investigative Ophthalmology & Visual Science, 56, 4520-4530