Perception and Motor Skill in Reading Shot Location in Beach Volleyball - Part II

Participants, Method, Stimulus and Procedure

The VU team invited 32 participants who were 8 expert beach players, 8 expert beach coaches, who formerly were expert players, 8 expert referees, who had not reached expert levels of play, and an inexperienced control group of 8 novices to participate.  Each group watched video clips of attacking sequences and predicted the depth and direction of the shot at various times before the attack.

All of the clips were culled from 25 women’s World Tour beach volleyball matches and included a pass, a set and an attack.  They were recorded approximately 6 meters behind the end-line, from the perspective of a defensive player.  Videos were progressively occluded at three different times:  (a) at setter-ball contact, (b) when the set was half-way to the hitter, and (c) at hitter-ball contact.[5]  Sequences were balanced for attacks from the left- and right-side, and in all sequences the blocker stayed at the net.   Also, because the defender was in view, clips equally balanced correct and incorrect anticipatory movements by the defensive player.  After viewing each sequence, participants had three seconds to decide whether the ball was attacked to the short or deep line or to the short or deep angle.[6]

Motor Experience Contributes to Reading Ability

Analysis of overall performances revealed that the expert players and coaches predicted shot location more accurately than novices, while the referees did not.   In addition, players outperformed both referees and novices in the latest occlusion condition.[7]  Accordingly, since “the group with the highest perceptual-motor expertise (and, notably, less watching experience) outperformed experience watchers,” the findings suggest that perceptual motor experience does contribute to anticipatory skills in beach volleyball.

An issue for further research, according to the authors, will be to study whether players were better readers because they more efficiently utilized cues from the video frame showing hitter-ball contact (3^rd occlusion point) or because they were superior at culling information from the entire offensive sequence.

Reading Depth and Direction

Comparing results on depth and direction the results indicate that reading the shot depth in beach volleyball is significantly more difficult than reading shot direction.   Overall accuracy scores were higher for direction predictions than depth judgments in the latest occlusion condition with players, coaches and referees all outperforming novices in reading whether the ball was attacked cross-court or down the line.  The available evidence therefore suggests that coaches should include more opportunities in practice for players to read cues indicative of short and deep shots in the game.  Knowledge of this weakness may also counsel in favor of positional adjustments to defensive players and movement training to improve overall small area quickness and account for potential depth related mis-reads in the game

Conclusion

Like the indoor game, the sport of beach volleyball is overwhelmingly played between contacts.  While those contacts are extremely important indicators of success, the ability to anticipate opponent’s intentions and prepare for the next contact is a proven skill variable separating the most accomplished players from their less skilled counterparts.

Over a decade ago, sports science determined that “[t]here is little doubt . . . that the ability to extract and use the information available from an opponent’s movement pattern is a limiting factor to successful performance for less skilled performers.”[8].  The results of the present study provide experimental evidence that motor experience gained from playing beach volleyball contributes to the ability to anticipate opponent shots both directionally and for depth.  The findings also suggest training emphases and strategies for improving performances in the game.

Since its birth on the shores of southern California, the sport of beach volleyball is now an emerging collegiate sport in the United States, has enormous worldwide popularity, and is an official summer sport of the Olympic Games.  As research science continues to teach us how great readers anticipate we coaches have an obligation to learn the science of the sport and develop principled methods for training the next generation of beach volleyball athletes.  

NOTES

[1] Aglioti, S.M., Cesari, P., Romani, M., Urgesi, C. (2008).  Action anticipation and motor resonance in elite basketball players.  Nature Neuroscience, 11, 1109-1116; Schutz-Bosbach, S., Prinz, W. (2007).  Perceptual resonance: Action-induced modulation of perception.  Trends in Cognitive Sciences, 11, 349-355.

[2] Aglioti, S.M., Cesari, P., Romani, M., Urgesi, C. (2008).  Action anticipation and motor resonance in elite basketball players.  Nature Neuroscience, 11, 1109-1116.

[3] Urgesi, C., Savonitto, M. M., Fabbro, F., & Aglioti, S. M. (2012). Long- and short-term plastic modeling of action prediction abilities in volleyball.  Psychological Research, 76, 542-560.

[4] Canal-Bruland, R., Mooren, M., Savelsbergh, G. (2011).  Differentiating expert’s anticipatory skills in beach volleyball.  Research Quarterly for Exercise and Sport 82:4 667-674.  I am grateful to Professor Canal-Bruland for providing me with a copy of the research.

[5] For an excellent discussion of the possible limitations of occlusion paradigms, see van der Kamp, J., Rivas, F., van Doorn, H., & Savelsbergh, G. (2008).  Ventral and dorsal contributions in visual anticipation in fast ball sports.  International Journal of Sport Psychology, 39, 100-130.

[6] Two stimulus conditions of the study have limiting effects.  First, it is unclear what impact, if any, visible blocker’s movements played in the participant’s predictions.  Also, anticipation ability was measured as a function of viewing randomized progressively occluded clips of offensive sequences.  Therefore, anticipation scores did not account for participant’s abilities to utilize other cues that commonly inform defensive reads in beach volleyball such as situational factors, opponent’s recent history and pattern recognition. 

[7] Only in the latest occlusion condition (at hitter-ball contact) did participants predict shot location more accurately than chance.

[8] Farrow, D., Abernathy, B. (2002).  Can anticipatory skills be learned through implicit video-based perceptual training?  Journal of Sports Sciences 20, 471-485.

Perception and Motor Skill in Reading Shot Location in Beach Volleyball - Parts I & II

Elite sports performers possess the twin abilities to repeatedly execute complex actions and anticipate the behavior of other players.  Indeed, anticipatory skill is one of the most clearly established variables distinguishing highly successful athletes from their less accomplished counterparts.

In the sport of volleyball, anticipation is a key ingredient in successful performance.   Blockers who can read setter and hitter intentions, passers who can read servers and ball flight, and defenders who can anticipate shot speed, depth and direction all have an advantage over players whose anticipatory skills are less developed.

The ability to read is likewise critical to success in the beach game.  With more court to cover and fewer teammates to help, defensive success in beach volleyball is inextricably intertwined with the ability to anticipate an opponent’s offensive intentions.   The growing dynamics of beach volleyball offenses, fewer blockers at the net compared to indoors and a playing surface that constrains small area quickness highlight the need for beach defenders to develop acute reading abilities.

How Do Great Readers Anticipate?

We’ve all seen volleyball players who just seem to know where the ball is going.  So how did they do it, and why are some athletes better than others in figuring out their opponents?  As it turns out, athletes with superior reading abilities do some rather than unique things that less capable readers do not. 

Principles garnered from scientific literature show that elite athletes: (1) make superior use of anticipatory visual cues, (2) utilize unique perceptual strategies, (3) employ efficient visual search patterns, (4) exhibit fast information-movement coupling (integrating vision and action); and (5) demonstrate superior pattern recognition ability.  Essentially, superior readers see the game in a very unique way from others -- but their perceptual expertise is not the whole story.

While we know that elite athletes are better than novices at reading, and we know a lot about how they do it, we still don’t know everything that contributes to the why?  Why is it that some athletes see the game so uniquely, extracting information from everything that’s going on, and thus are better able to accurately predict what is about to happen?  

Perceptual vs. Motor Experience

One of the most important questions scientists are studying to better understand the skill of reading is whether elite athlete’s motor skills in addition to their perceptual experience contribute to anticipation abilities.

There are two related accounts.

In one view, anticipation ability is a function of perceptual experience.  In this view, elite level athletes’ extensive exposure to the game enhances their sensitivity to the relevant cues that reveal what other players intend to do.

Another view says that athletes’ motor skills also have something to do with it.  This view links perceptual experience with motor experience by positing that skilled athlete’s motor experience contributes to their superior anticipation abilities. 

The developing idea is that athletes are perceptually better attuned to actions within their own motor repertoire.  Thus elite athletes are better at identifying the kinematic cues that indicate in others an intention to perform the same or similar skills the athletes themselves are capable of performing.[1]  Research comparing the anticipation ability of elite level athletes with those possessed primarily of perceptual experience alone (e.g., coaches, referees and fans) seems to support this view.   

For example a team of Italian researchers found that expert basketball players were able to predict the success of free throws more accurately and quickly than coaches and journalists who lacked playing experience.[2]  Evidence published this year similarly found that volleyball athletes were better able to utilize kinematic information to predict the fate of float serves more accurately than expert watchers and novices who did not play the game.[3]

Anticipation in Beach Volleyball Defense

A new study from researchers at the VU University in Amsterdam recently contributed to our understanding of elite reading ability in the sport of beach volleyball.

The researchers brought together beach volleyball players, coaches, referees and novices to compare their performances in a beach volleyball defensive reading experiment.  The VU team sought to isolate participants with perceptual experience (referees) from participants with perceptual and motor experience (players and coaches) in order better to understand the contributions of perceptual and motor experience to action anticipation in beach volleyball.

Based on current research suggesting that motor experience does contribute to anticipatory skills, the team predicted that the players and coaches would perform better than the referees and novices.  The research was published in the Research Quarterly for Exercise and Sport.[4]

[Continued in Part II - click here]

The Role of Observation and Motor Experience in Reading a Float Serve in Volleyball

The importance of service reception in women’s volleyball is well established.  Statistical data consistently have confirmed the close correlation of multi-option passing and winning.  One of the most basic elements of success in serve receive is the ability to predict the flight of the ball.  Misjudgments in ball flight commonly produce poor passes and single option passes are extremely inefficient events in the game.  Thus, developing players with the skill to accurately predict the flight of the ball during the serve receive phase of the game should be a high coaching priority.

So how do we get our players to make these predictions?  Do we recruit players that we think have an innate ability to track a ball?  Do we wait for players with excellent reading skills to just walk into the gym?  The answer is we train them.  Action prediction ability in sport is neither a magical quality nor an innate talent.  It’s a learned skill, and like any skill, it should be trained from the earliest stages of a player’s development and continuously honed throughout her career.  As reading is perhaps the most important skill in the game, the more we know about it the better we can teach it.

A recent study published in Psychological Research offers valuable insights into the elements that contribute to successful service-reading abilities in volleyball players[1].

Action Prediction Abilities in Volleyball

A team of Italian researchers examined the role of visual and motor experience in the ability of athletes to predict the action of float serves in volleyball.  The authors compared the reading abilities of three groups of adult, right-handed females in their mid-twenties.  Group 1 consisted of 12 volleyball athletes with about 15 years of playing experience (experts).  Group 2 was comprised of 12 supporters who had no experience playing volleyball but who had regularly attended to watching volleyball for at least 10 years (watchers).  Group 3 was comprised of 12 adults with no volleyball experience at all (novices).

Participants were shown video clips of two experienced players performing a series of float serves.  Videos showed a front- and back-view of the server.  Clips were shown using a modified temporal occlusion in which only the body movements of the server or only the ball was shown.  Half of the clips showed the beginning of the action to the point of the server’s contact with the ball, thus showing only the server’s body kinematics; the other half showed the moment of contact to the initial falling trajectory of the serve (when it was approximately at the height of the net), thus showing only the ball trajectory.

   

Participants were asked to view the clips and predict as fast as possible whether the ball was served in our out of the court.  Notably, in the front-view perspective the ball was not fully visible in the last part of ball trajectory – when the ball was falling to the floor.

Study Results

What the researchers found was a mix of predictable and not so predictable results.  The volleyball athletes outperformed the novices in predicting serves both from reads based on the server’s body kinematics and the ball trajectory – regardless of the viewing perspective.  These results confirm years of research consistently showing the superior action-prediction abilities of elite athletes in their sports, including volleyball.

So what about the watchers?  Did their visual experience contribute to accurate predictions although they had no playing experience?  The evidence suggests that it did.  Although watchers were again outperformed by athletes, the watchers outperformed novices in one important phase - predicting the serve when viewed from behind the server.    

According to the authors, since the late stages of ball flight stayed in view only for the back-view clips, the watchers’ visual experience seems to have improved only their ability to read the serve by using this late ball flight information.  In contrast, the volleyball athletes showed proficiency in utilizing both early and late cues from ball trajectory which were visible in both the front and back view videos.

Significance for Coaching

The participant-athletes’ superior performance in predicting ball flight based on the server’s body movements confirms again the profound implications of teaching players how to read.  With serve reception playing a critical role in winning volleyball matches coaches should be eager to incorporate ways to improve players’ serve-receive reading skills.

So how do we do this?

Serve Receive Actual Serves - Reading the Server

Serving and passing must occupy a significant portion of practice time.  Passers should be passing live serves – and lots of them.  Success in predicting ball flight in volleyball comes in part from the twin abilities to recognize cues in the server’s behavior and then link those cues to results.  When coaches toss balls to players or chip balls in from the sideline, players are robbed of the cues they need to learn from actual servers and consequently are deprived of valuable opportunities to link cues with results.   Only through receiving served balls from real servers do players have an opportunity to identify and interpret the kinematic cues of real servers and develop the motor experience that is essential to predicting the flight of served volleyballs.

But we can’t just set up serving and passing games.  Like all training, serve receive practice should be accompanied by effective feedback.  We should coach players what cues to look for, ask them what they see, and guide them to understand the connection between what they see and how the ball reacts.  Practice with feedback is the only principled basis for teaching the skill of reading.

Importance of Early Ball Flight - Reading the Ball

In addition to planning lots of serving and passing games coaches must emphasize the value of early preparation in serve receive.  The instant research suggests that athletes’ advanced reading abilities are tied to their unique skills in reading both kinematic cues and the initial phase of ball trajectory.  In other words, athletes draw heavily from what is happening on the other side of the net.  Emphasizing early visual preparation teaches athletes that much of their success in service reception can be determined long before their “technique” comes into play.

NOTES

[1]   Urgesi, C., Savonitto, M. M., Fabbro, F., & Aglioti, S. M. (2012). Long- and short-term plastic modeling of action prediction abilities in volleyball.  Psychological Research, 76:542-560.

The Home Court Advantage in Volleyball: Fact, Fiction and Mystery

Playing and Coaching at Home

Everyone knows there are advantages to playing at home.  You get to sleep in your own bed, eat your own food, and you don't have to pack a bag.  No airports, airplanes or bus rides.  When you arrive at the gym you're in familiar surroundings.  You know the locker room, the gym, the lighting and the floor.  You know the space around the court and the height of the ceiling.  Friends and family watch and support you.  You're as comfortable as you can be before a match.

Life is good. . . .  

The Home Advantage in Sports

But wait, it gets even better.  If there are advantages to playing at home there's also a home court advantage.    Depending on who you listen to home teams win 52% of all baseball games, 58% of football games and 66% of basketball games.[1]  Whatever the reasons (nobody seems to know why) home teams win more often than visitors[2].  Could there be a home court advantage in volleyball too?  Some researchers say yes. 

Home Advantage in Volleyball

In the first research study of its kind researchers in Portugal examined whether there is a home court advantage in volleyball by analyzing 275 volleyball games played in the 2005 Men's Senior World League.  They concluded that home teams in volleyball have a greater probability of winning across all sets and have a greater advantage at the beginning and end of a match.  The study is published in the Journal of Sports Science and Medicine.[3]

While there are many great benefits to playing and coaching at home, it's still not clear why home teams have more success.  Across sports the research is ambiguous and unfortunately the current study sheds little more light on the subject.  

While stopping short of offering "causes," the authors posit varied possible explanations for their findings including: (a) a perception of social support for the home team reduces stress and promotes performance; (b) home teams' greater familiarity with "situational variables" allow them to outperform opponents who need more time in a match to adjust; and (c) support and familiarity factors maximize home teams' advantages in the most critical points in a match (the 1st and 5th sets), justifying a higher probability of winning those sets.

The precise reasons for the home advantage, and whether it extends beyond the men's senior world league in volleyball, awaits further exploration.  Until then, players and coaches, enjoy those home matches and train to get better on the road.


NOTES

[1] Albert, J., Bennett, J. (2003)  Curve ball: Baseball, statistics and the role of chance in the game. New York: Copernicus Books.

[2]  For an interesting discussion of possible reasons I recommend Tobias Moskowitz and L. Jon Wertheim's new book, Scorecasting: The Hidden Influences Behnd How Sports Are Played and Games Are Won.

[3]  Marcelino, R., Mesquita, I., Palao, J., Sampaio, J. (2009).  Home advantage in high-level volleyball varies according to set number.  Journal of Sports Science and Medicine. 8, 352-356.

Of Cognitive Fallacies, Streaks and the "Hot Hand" in Volleyball

Human Frailty

For many years psychologists have studied the human tendency to see patterns where none exist.  We look for patterns in random data and we see patterns in random events.  In studies of probability guessing where colors are randomly presented, but weighted to appear with different probabilities, humans guess the next color by trying to guess the pattern and rats just go with the color that appears most often in the series, and with that, humans allow themselves to be outperformed by rats.[1]

We don't do so well analyzing situations involving chance.  We do even worse when we feel uncertain or out of control.  Randomness fools us because we don't recognize it.  We like to make sense of the world by seeing patterns and assigning to every event a distinct and definite cause.  So our thinking leads us to misinterpret all kinds of events around us and to make decisions that sometimes are less than optimal and other times are flat out wrong.[2]

The world is full of "patterns of randomness" - streaks - that are routinely misinterpreted and then relied upon as if they portended a trend.  In our oceans of data we struggle to interpret correctly and sometimes see meaning where none exists.  Indeed, that's why most readers will see (or suspect) a pattern in this random sequence:      

OXXXOXXXOXXOOOXOOXXOO[3]

We see patterns everywhere, but perhaps in no context do we do so more fervently than in sports.  So let's look at our bias toward patterns as it manifests itself in the popular belief in the "hot hand."
 
The "Hot Hand"

The "hot hand" in sports has been debated for years.  Is a basketball player more likely to continue shooting well after making his first four shots?  Will a volleyball player more likely get a kill after putting away the last three balls?  Athletes, coaches and fans nearly universally accept that players running a streak of success are more likely to continue succeeding on subsequent attempts until they "cool off."

But is this really true?  Is there any such thing as a "hot hand" in sports or are we just seeing random streaks of success within a much larger performance range and body of work?  Is each hit, goal and kill independent of the one before (as in flipping a coin) or does the streak of success drive further success? 

Fallacy or Not?

In the seminal study of the hot hand in sports, psychologist Thomas Gilovich and his colleagues looked at streak shooting in basketball.[4]  Extensive shot analysis revealed no evidence that a player's chance of hitting a shot was greater following a hit than following a miss.  Indeed, Gilovich found that for nearly 90 percent of players studied, the probability of making a shot was actually slightly lower following a make than following a miss.  Accordingly, it was concluded that belief in the "hot hand" was merely "an erroneous perception of a positive correlation between successive shots" - in other words, a cognitive fallacy.

Research since then has by and large reached a similar conclusion, leading some experts to summarily state that empirical evidence of the existence of the hot hand in sports is "considerably limited."[5]

Though the hot hand may be a myth, research has spawned analysis of some interesting questions on the periphery.  Researchers have questioned what impact opponent's defensive changes have on detection of the "hot hand."  Others have examined whether belief in the hot hand, even if fallacious, can beneficially drive in-game allocation decisions and result in the optimal player getting the ball[6].

"Hot Hand" Revisited - Attacking Streaks in Volleyball

In the last six months a group of German researchers re-visited the hot hand phenomenon to determine whether it exists in the sport of volleyball and whether belief in it drives players' and coaches' decisions to distribute the ball to particular players.  The research is published in the Journal of Experimental Psychology: Applied[7].

Defining the Hot Hand

When we speak of the "hot hand" we mean more than just a performance streak.  Streaks in sports occur all of the time and have been shown in a variety of settings.  We all know that baseball players can get three or four hits in a row and volleyball players can get three or four straight kills.  A belief in the hot hand, however, refers to a belief that the streak portends a greater likelihood of success on each successive attempt.  Thus researchers in the present study defined a hot hand as a "higher probability  . . . to score again after two or more [kills] compared with two or three [hitting errors]."

What they found was rather interesting:  the hot hand exists in volleyball; athletes and coaches overwhelmingly believe in it; and both rely on it to make allocation decisions in the game.

Summary of Results

To determine whether athletes believe in the hot hand in volleyball the authors asked 94 sports science students with athletic experience at the German Sport University Cologne to respond to a questionnaire on the subject.  Eighty-six of the ninety-four athletes (91%) reported believing in the hot hand in volleyball.   In other samples taken, 90% of 21 other athletes reported and 92% of coaches also reported believing in the hot hand.

The authors next sought to determine whether that belief was founded. To determine whether a hot hand does in fact exist the researchers analyzed game performances of 26 male volleyball players from the top volleyball league in Germany.  They found that half of the players experienced a hot hand phenomenon and half did not.

Given that the hot hand appeared to exist for some players but not everyone, the authors examined how setters use their belief in the hot hand to distribute the ball.  Setters in an experiment were sensitive to both a hot hand belief and overall hitting percentages, but the "hot hand" belief was the stronger cue in actual set distribution.

Significantly, the researchers found that setters more often distributed the ball to players experiencing streaks of success and this lead to better performance than when setting the ball to the player with the higher average hitting percentage.  The authors cautioned, however, that a distribution strategy that ignores hitting percentage would be less than optimal where the differences in hitting percentage between the "hot" and the "non-hot" player compensate for the advantage of setting the streak. 

The German authors are not the first to posit that optimal play may result from setting the player with the perceived "hot hand."  A study published in 2001 by a psychologist at the University of Michigan showed that distributing the ball to the player perceived to be "hot" in basketball positively impacts the team regardless whether the hot hand phenomenon actually exists.

The studies' author demonstrated that basketball players with higher shooting percentages experience more streaks of made shots, so when streak shooting produces a perception of "hotness," distributing the ball to the "hot hand" actually results in the best shooting player getting the ball more often[8].

Why Do We Care?

So what does all this mean?  As a volleyball coach I really don't know whether the "hot hand" phenomenon exists in volleyball or not.  I do know that collectively I've played in, watched and coached thousands of volleyball games and sometimes players hit hot streaks and sometimes players hit cold streaks.  What to do with that information - I'm still learning.

But uncertainty should not shroud the more fundamental point of research on the subject - that people, coaches included, tend erroneously to detect patterns in random data and often make poorer judgments because of it.  Recognition of this fact - of the frailty of our own thinking - should inform and improve the process by which we all make decisions.

As coaches we make thousands of decisions every season.  We make personnel decisions, we decide tactics, strategies, and systems of play.  We choose whether, how and when to give feedback.  We decide whether to run practice, how long it will be, and what its design will consist of.  We even decide who will be on our teams and whether and how often they will play.  Our thinking and our choices permeate our programs and touch the lives of many, many people.  With research continuously showing our impact on the lives of other people we should care deeply about how we make decisions and at least be aware of our own frailties.  We owe it to our players and the profession to constantly search for ways to improve.

NOTES

[1]  Mlodinow, L., (2009).  The drunkard's walk: How randomness rules our lives.  New York: Vintage Books.

[2]  For two excellent books on how we make decisions when faced with uncertainty I recommend Leonard Mlodinow's The Drunkard's Walk: How Randomness Rules Our Lives and Thomas Gilovich's How We know What Isn't So: The Fallacy of Human Reasoning in Everyday Life.

[3]  Gilovich, T. (1991).  How we know what isn’t so: The fallibility of human reason in everyday life.
New York: The Free Press.

[4]  Gilovich, T., Vallone, R., Tversky, A. (1985).  The hot hand in basketball: On the misperception of random sequences. Cognitive Psychology 17: 295–314.

[5]  Bar-eli, M., Avugos, S., Raab, M., (2006). Twenty years of hot hand research: Review and critique.  Psychology of Sport and Exercise 7(6): 525-553. 

[6]  Burns, B. D. (2001). The hot hand in basketball: Fallacy or adaptive thinking? In J. D. Moore, & K. Stenning (Eds.), Proceedings of the Twenty-third Annual Meeting of the Cognitive Science Society (pp. 152-157). Hillsdale, NJ; Lawrence Erlbaum; Raab, M., Gula, B., Gigerenzer, G. (2012).  The hot hand exists in volleyball and is used for allocation decisions.  Journal of Experimental Psychology: Applied 18(1): 81-94.

[7]  Raab, M., Gula, B., Gigerenzer, G. (2012).  The hot hand exists in volleyball and is used for allocation decisions.  Journal of Experimental Psychology: Applied 18(1): 81-94 (available here).

[8] Burns, B. D. (2001). The hot hand in basketball: Fallacy or adaptive thinking? In J. D. Moore, & K. Stenning (Eds.), Proceedings of the Twenty-third Annual Meeting of the Cognitive Science Society (pp. 152-157). Hillsdale, NJ.

Visual Search Pattern Analysis Reveals Differences in How Experts and Novices See the Serve in Volleyball

In the sport of volleyball, service reception is best accomplished by athletes capable of identifying and interpreting relevant visual cues from the server and the ball and predicting where the ball will be served to and where it will arrive.  Indeed the essential key to passing, like playing defense, is the ability to anticipate the future both efficiently and correctly. 

Part of this process of anticipation involves athletes’ visual search patterns -- their eye movements -- while performing a volleyball skill.  Recent research has shed some light on this process, which helps explain one of the significant performance differences between experienced and inexperienced volleyball players.

In a study published in the International Journal of Applied Sports Sciences, researchers examined the visual search patterns of expert and novice volleyball players receiving serve and found that the two groups not only focused on different cues during the act of serving but also began tracking the ball at distinctly different times.[1]

Experts focused more on the server’s arm and shoulder area than novices did[2] and experts began tracking the flight of the serve significantly earlier than their novice counterparts.[3]  These findings suggest an important evidence-based approach to coaching reading in service reception.

It was also revealed that experts were capable of predicting the arrival point of the serve, resulting in their eyes coming off the ball immediately prior to contact, [4] while novices were unable to predict the target point and instead tried to maintain tracking all the way to contact with their platform (see Fig 1 – reproduced from original work).  This conclusion may dispel a volleyball coaching myth that passers should strive to track the ball directly into the platform.

Fig. 1

Figure 1. Frames from the mobile eye tracker video, showing the receiver’s view between expert (E) and novice (N) during the flight phase, and the direction foveal gaze as he watches it.

(1 = serve impact; 2 = 2frame after impact; 3 = 4frame after impact; 4 = ball flight peak point; 5 = 0.18sec before serve reception; 6 = 2frame before serve reception).

NOTES

[1] Lee, S. (2010).  Does Your Eye Keep on the Ball?:  The Strategy of Eye Movement For Volleyball Defensive Players During Spike Serve Reception.  Int’l J. Applied Sports Sciences, 22(1) 128-137.

[2] Location variables were the server’s shoulder, arm, head, and impact point of the hand with the ball.  Experts fixated in the server’s shoulder and arm area for 66.20% of total locations.  Novices fixated on the same areas only 7.46% of total locations.

[3] Experts began tracking the ball within a mean of 0.14 seconds after the server's contact with the ball.  Novices had a mean tracking onset of 0.21 seconds – a rate nearly 33% slower than the expert.

[4] For experts, the time between the last eye fixation on the ball and actual reception was less than 0.18 seconds.