Anticipation in squash: differences in advance cue utilization between expert and novice players

The time of occurrence and spatial location of the advance cues used to anticipate the direction and force of an opponent's stroke in squash were examined using a film task. This task, designed to stimulate the normal perceptual display of the defensive player, consisted of two discrete parts, each containing 160 individual stroke sequences (trials). In the first part of the film task, the display was occluded at different time intervals throughout the development of the opponent's stroke and the 16 expert and 20 novice subjects had to predict both the direction (down-wall or cross-court) and force (drive or drop shot) of the opponent's stroke. In the second part of the film task, visibility to selected advance cues was occluded by placing opaque mats on the film surface. Across all of the film task conditions experts were superior to novices in predicting the event outcome from the information available, highlighting the important contribution anticipatory skills make to expert performance in this sport. Analysis of lateral (direction) error showed that the most critical time periods for extracting information about stroke direction are the periods between 160-80 ms prior to racket-ball contact and the period of extended ball flight arising at least 80 ms after contact. Whereas both groups were attuned to this ball flight information, only the experts were capable of picking up information from the early part of the opponent's actions. This early information appeared to be provided by the opposing player's arm action. Similar time periods were found to be also important for the prediction of stroke depth, but in this case both experts and novices were similar in their cue dependence.     

Quantifying the nature of anticipation in professional tennis

Abstract

We quantify the nature and frequency of anticipation behaviours in professional tennis using video coding of incidents where the time delay between the opponent's stroke and the reaction of the player were recorded. We argue that anticipation is based on uncertain information and should lead in some situations to erroneous decisions. We identified the transition between reaction (with 100% accuracy in the selection of where the ball is played on the court) and anticipation (with less than 100% accuracy) as being 140–160 ms after ball contact. Anticipation behaviours occurred on between 6.14% and 13.42% of the coded situations. These anticipation behaviours appeared almost exclusively in ‘unfavourable’ situations, where the opponent had a significant tactical advantage, with the type of playing surface having only a limited effect. Moreover, the decrease in accuracy with shorter response times is not monotonic, with an increase in response accuracy being observed for times shorter than 120 ms before ball contact. We propose that very early anticipation behaviours occur when players use significant context-specific information before the opponent's stroke. When such information is not available, players produce anticipation behaviours that are closer to the moment of ball–racket contact using information that is more likely to be based on the opponent's preparation of the stroke. This study opens new directions for research focusing on the testing and training of anticipation in fast ball sports.     

On the tactical significance of game situations in anticipating ball trajectories in tennis

It is hypothesized that live playing situations preceding an opponent's strokes in tennis have sufficient significance to provide expert players with anticipative cues to estimate accurately the spatiotemporal characteristics of oncoming ball trajectories. Seven participants (all expert tennis players) had to watch two players opposed in high, moderate, and low tactical significance situations terminated by a stroke delivered by one of the two players in the direction of the participants. The participants' vision was occluded 100 ms after the stroke, and they had to indicate the zone reached by the ball at the moment of its rebound. Results showed that the essential anticipative information is contained in the view of the opponent's stroke movements, whatever the tactical significance of the situation.     

Microsaccades and interest areas during free-viewing sport task

Microsaccades are important fixation eye movements for visual scene perception. Compared to novices, athletes make fewer fixations of longer duration toward limited interest areas crucial for action prediction. Thus, our aim was to study the microsaccade features during those fixations. Gaze behaviour of expert and novice table tennis players was recorder during a task in which subjects were instructed to predict the direction of the ball after the opponent’s throw. Three interest areas from the opponent’s body and one from the ball trajectory were identified. We analysed correctness of predictions, fixations, microsaccades and saccades to estimate the relationship between eye movements toward interest areas and success in the task. Compared to novices, experts fixated more on hand-racket during forehand and on trunk during backhand drive technique. Longer fixations on hand-racket and trunk were associated with higher microsaccade rate with a narrower directional distribution of them. It probably means that athletes focused their gaze on these small areas, suggesting enhanced attention mainly to them, and fewer consideration for the surrounding regions. We can assume that microsaccade rate and average direction could be related to the salience of interest areas during performance.     

Prediction of shot success for basketball free throws: Visual search strategy

Abstract

In ball games, players have to pay close attention to visual information in order to predict the movements of both the opponents and the ball. Previous studies have indicated that players primarily utilise cues concerning the ball and opponents' body motion. The information acquired must be effective for observing players to select the subsequent action. The present study evaluated the effects of changes in the video replay speed on the spatial visual search strategy and ability to predict free throw success. We compared eye movements made while observing a basketball free throw by novices and experienced basketball players. Correct response rates were close to chance (50%) at all video speeds for the novices. The correct response rate of experienced players was significantly above chance (and significantly above that of the novices) at the normal speed, but was not different from chance at both slow and fast speeds. Experienced players gazed more on the lower part of the player's body when viewing a normal speed video than the novices. The players likely detected critical visual information to predict shot success by properly moving their gaze according to the shooter's movements. This pattern did not change when the video speed was decreased, but changed when it was increased. These findings suggest that temporal information is important for predicting action outcomes and that such outcomes are sensitive to video speed.     

Visual search, anticipation and expertise in soccer goalkeepers

We used a novel methodological approach to examine skill-based differences in anticipation and visual search behaviour during the penalty kick in soccer. Expert and novice goalkeepers were required to move a joystick in response to penalty kicks presented on film. The proportion of penalties saved was assessed, as well as the frequency and time of initiation of joystick corrections. Visual search behaviour was examined using an eye movement registration system. Expert goalkeepers were generally more accurate in predicting the direction of the penalty kick, waited longer before initiating a response and made fewer corrective movements with the joystick. The expert goalkeepers used a more efficient search strategy involving fewer fixations of longer duration to less disparate areas of the display. The novices spent longer fixating on the trunk, arms and hips, whereas the experts found the kicking leg, non-kicking leg and ball areas to be more informative, particularly as the moment of foot-ball contact approached. No differences in visual search behaviour were observed between successful and unsuccessful penalties. The results have implications for improving anticipation skill at penalty kicks.     

Cricket bowling deliveries and the discrimination ability of professional and amateur batters

Bowlers in cricket try to disguise their bowling action by movement pattern similarity. The batter’s task is, therefore, to solve rapidly perceptual discrimination problems. Previous research has suggested that batters can discriminate perceptual cues that provide depth or target information. However, at present, there is a lack of applied research evidence on further perceptual cue utilization, including bowling delivery identification. This ability is required when batting against wrist-spin bowlers who may use five different types of delivery. In the present study, we assessed this perceptual discrimination ability among three distinct standards of batters. In addition, the relative potency of body action and ball flight information was assessed by visual occlusion techniques. We found that more expert batters in general showed greater perceptual discrimination skills when faced with different ball types. However, this discrimination ability was linked specifically to delivery type and to previous experience. We also found that additional ball flight information provided no more advantage to this discrimination ability. This finding reinforces the importance of advanced cue information and the need to expose cricket batters to different bowling actions. Further study of the development of movement pattern recognition is recommended.     

Adaptability of expert visual anticipation in baseball batting

By manipulating stimulus variation in terms of opponent pitcher actions, this study investigated the capability of expert (n = 30) and near-expert (n = 95) professional baseball batters to adapt anticipation skill when using the video simulation temporal occlusion paradigm. Participants watched in-game footage of two pitchers, one after the other, that was temporally occluded at ball release and various points during ball flight. They were required to make a written prediction of pitch types and locations. Per cent accuracy was calculated for pitch type, for pitch location, and for type and location combined. Results indicated that experts and near-experts could adapt their anticipation to predict above guessing level across both pitchers, but adaptation to the left-handed pitcher was poorer than the right-handed pitcher. Small-to-moderate effect sizes were found in terms of superior adaptation by experts over near-experts at the ball release and early ball flight occlusion conditions. The findings of this study extend theoretical and applied knowledge of expertise in striking sports. Practical application of the instruments and findings are discussed in terms of applied researchers, practitioners and high-performance staff in professional sporting organisations.     

Cricket bowling deliveries and the discrimination ability of professional and amateur batters

Bowlers in cricket try to disguise their bowling action by movement pattern similarity. The batter's task is, therefore, to solve rapidly perceptual discrimination problems. Previous research has suggested that batters can discriminate perceptual cues that provide depth or target information. However, at present, there is a lack of applied research evidence on further perceptual cue utilization, including bowling delivery identification. This ability is required when batting against wrist-spin bowlers who may use five different types of delivery. In the present study, we assessed this perceptual discrimination ability among three distinct standards of batters. In addition, the relative potency of body action and ball flight information was assessed by visual occlusion techniques. We found that more expert batters in general showed greater perceptual discrimination skills when faced with different ball types. However, this discrimination ability was linked specifically to delivery type and to previous experience. We also found that additional ball flight information provided no more advantage to this discrimination ability. This finding reinforces the importance of advanced cue information and the need to expose cricket batters to different bowling actions. Further study of the development of movement pattern recognition is recommended.     

Anticipation by basketball defenders: An explanation based on the three-dimensional inverted pendulum model

Abstract

We previously estimated the timing when ball game defenders detect relevant information through visual input for reacting to an attacker's running direction after a cutting manoeuvre, called cue timing. The purpose of this study was to investigate what specific information is relevant for defenders, and how defenders process this information to decide on their opponents' running direction. In this study, we hypothesised that defenders extract information regarding the position and velocity of the attackers' centre of mass (CoM) and the contact foot. We used a model which simulates the future trajectory of the opponent's CoM based upon an inverted pendulum movement. The hypothesis was tested by comparing observed defender's cue timing, model-estimated cue timing using the inverted pendulum model (IPM cue timing) and cue timing using only the current CoM position (CoM cue timing). The IPM cue timing was defined as the time when the simulated pendulum falls leftward or rightward given the initial values for position and velocity of the CoM and the contact foot at the time. The model-estimated IPM cue timing and the empirically observed defender's cue timing were comparable in median value and were significantly correlated, whereas the CoM cue timing was significantly more delayed than the IPM and the defender's cue timings. Based on these results, we discuss the possibility that defenders may be able to anticipate the future direction of an attacker by forwardly simulating inverted pendulum movement.     

Analysis of the relation between throwing speed and throwing accuracy in team-handball according to instruction

Abstract

This study examines the differences between expert and novice team-handball players in their sensitivity to instructions that emphasize speed or precision requirements. The effects of instructions on throwing speed and accuracy of a handball over arm throw and the speed–accuracy trade-off in experts and novices is revisited. An expert group (n=18) with a training experience of more than 10 years, and a novice group (n=24) without experience in team-handball, took part in the study. The participants were asked to throw to targets located at different positions following instructions emphasizing accuracy and instructions emphasizing accuracy and speed. Throwing speed was measured with a speed gun radar, and the centre of the ball when the ball entered the goal was digitalized for accuracy. Under these experimental conditions, the novice group was sensitive to instructions for reducing throwing speed and increasing accuracy when instructions emphasized accuracy. The expert group increased throwing speed when the instructions emphasized speed, but was not less accurate. The results indicate that it is advisable for experts’ speed to be close to maximum speed since it does not seem to have a significant effect on accuracy of the throw.     

The coupling between point-of-gaze and ball movements in three-ball cascade juggling: the effects of expertise, pattern and tempo

The relationship between point-of-gaze and ball movements in three-ball juggling was examined as a function of expertise, pattern and tempo. Five intermediately skilled and five expert jugglers performed the standard and reverse cascade at three tempos, while point-of-gaze and ball movements were recorded simultaneously. Scaled to the size of the ball patterns, the experts made smaller point-of-gaze movements than the intermediates, especially in the horizontal direction and in the standard cascade. In both skill groups, point-of-gaze and ball movements were often 1 : 1 frequency locked in the horizontal direction, whereas in the vertical direction 1 : 2 frequency locking also occurred. In the latter direction, the 1 : 1 ratio prevailed in the intermediates and the 1 : 2 ratio in the experts. In addition, the incidence of the 1 : 1 ratio decreased and that of the 1 : 2 ratio increased with increasing tempo. Furthermore, in the vertical direction, increasing tempo resulted in a weaker 1 : 1 locking, whereas the strength of the 1 : 2 ratio remained unaffected by tempo. In the horizontal direction, the strength of the 1 : 1 locking was higher on average in the reverse cascade than in the standard cascade. We conclude that expertise in juggling is reflected by an overall reduction in the extent to which the balls are visually tracked, and that task constraints such as tempo and juggling pattern affect the visual search patterns of both expert and intermediate jugglers.     

Variance and Invariance in Expert and Novice Triple Junipers

Abstract

The purpose of this study was to examine relative timing, relative distance, and effector independence characteristics of the triple jump. We videotaped expert and novice triple jumpers using standing and running starts. On some trials, the triple jumpers were required to take off from their nondominant leg. Gentner's (1987) interaction test was used to assess the proportional duration model in describing the timing of the component submovements. For both experts and novices, the proportional durations varied with the type of start. For experts, the relative timing of the jump components was independent of the take-off leg. The findings were mixed for the novices. Similar results were obtained when relative distance was examined. These results are discussed with respect to constructs related to variability in skilled performance.     

Cardiorespiratory,hormonal and haematological responses to submaximal cycling performed 2 days after eccentric or concentric exercise bouts

The aim of this experiment was to determine the effectiveness of two video-based perceptual training approaches designed to improve the anticipatory skills of junior tennis players. Players were assigned equally to an explicit learning group, an implicit learning group, a placebo group or a control group. A progressive temporal occlusion paradigm was used to examine, before and after training, the ability of the players to predict the direction of an opponent's service in an in-vivo on-court setting. The players responded either through hitting a return stroke or making a verbal prediction of stroke direction. Results revealed that the implicit learning group, whose training required them to predict serve speed direction while viewing temporally occluded video footage of the return-of-serve scenario, significantly improved their prediction accuracy after the training intervention. However, this training effect dissipated after a 32 day unfilled retention interval. The explicit learning group, who received instructions about the specific aspects of the pre-contact service kinematics that are informative with respect to service direction, did not demonstrate any significant performance improvements after the intervention. This, together with the absence of any significant improvements for the placebo and control groups, demonstrated that the improvement observed for the implicit learning group was not a consequence of either expectancy or familiarity effects.     

Automated processes in tennis: Do left-handed players benefit from the tactical preferences of their opponents?

Abstract

Previous research on laterality in sport suggests an over-representation of left-handers in interactive sports such as tennis and cricket. These findings potentially reflect left-handers' advantage over their right-handed competitors in those sports. Although considered crucial for successful performance, the tactical component of their superiority has yet to be analysed. Two studies were conducted to test for a side bias in tennis players' tactical preferences. In the first study, 108 right- and left-handed players of varying skill watched rallies on a computer screen and had to indicate where they would place the ball in the opposing half. The results showed the tactical preference of players to place more balls on a left-handed opponent's mostly stronger forehand side compared with when faced with a right-hander. In the second study, 54 professional tennis matches involving right- and left-handers were analysed with respect to ball placement frequencies on the opponent's backhand side. Significantly fewer balls were hit to the backhand side of a left-handed opponent, thus replicating the findings of Study 1 in on-court situations. Both studies indicate players' preference to place shots to their right irrespective of their opponent's handedness. Findings support the assumption that left-handers might enjoy a strategic advantage in tennis.     

Analysis of Gymnastics Judges' Visual Search

Abstract

This study was designed to investigate the visual search patterns of gymnastics judges. The subjects were four national judges (experienced) and three local judges (novice). Three dependent variables were measured: the number and the location of ocular fixations during the evaluation of a gymnast's performance, and the number of errors made by the judges. Ocular fixations were studied by the corneal reflection technique with a NAC Eye-Movement Recorder. There was no statistical difference in the number of fixations for both groups of judges. However, the expert judges had 27% less fixations than the novice judges. A statistical difference was found between expert judges and novice judges for the location of fixations; experts had more fixations on the upper part of the gymnast's body, while novices concentrated their attention on the legs. The type of routine significantly affected the number of fixations; more fixations were found for optional routines. There was no statistical difference in the number of judgment errors made by the two groups of judges. However, novice judges detected only half the gymnast's errors detected by the expert judges.     

Visual search,anticipation and expertise in soccer goalkeepers

We used a novel methodological approach to examine skill-based differences in anticipation and visual search behaviour during the penalty kick in soccer. Expert and novice goalkeepers were required to move a joystick in response to penalty kicks presented on film. The proportion of penalties saved was assessed, as well as the frequency and time of initiation of joystick corrections. Visual search behaviour was examined using an eye movement registration system. Expert goalkeepers were generally more accurate in predicting the direction of the penalty kick, waited longer before initiating a response and made fewer corrective movements with the joystick. The expert goalkeepers used a more efficient search strategy involving fewer fixations of longer duration to less disparate areas of the display. The novices spent longer fixating on the trunk, arms and hips, whereas the experts found the kicking leg, non-kicking leg and ball areas to be more informative, particularly as the moment of foot-ball contact approached. No differences in visual search behaviour were observed between successful and unsuccessful penalties. The results have implications for improving anticipation skill at penalty kicks.     

The use of heuristics during route planning by expert and novice orienteers

Expert orienteers have reported using two heuristics when planning routes to points in the environment that must be located, known as 'controls'. These heuristics constitute attending to the start first and subsequently planning forward to a given control, and attending to the control first and planning backwards to the start. The aim of this study was to establish which heuristic experts use predominantly and whether novices' use of these heuristics differs from that of experts. Two methods for tracing attention were used while 20 expert and 20 novice orienteers planned routes in the laboratory. The results were used to infer the use of heuristics. The orienteers were also interviewed about planning. We found that, when planning, experts generally attend to the control first and novices to the start first. There was also some evidence that novices work forwards from the start to the control and that experts work backwards from the control to the start. From the interviews, it would appear that experts regard the location of the control as the crux of the problem and prioritize this area during planning. These results have implications for an understanding of expertise and problem-solving in sport.     

Coordination as a function of skill level in the gymnastics longswing

The purpose of this study was to investigate the nature of inter-joint coordination at different levels of skilled performance to: (1) distinguish learners who were successful versus unsuccessful in terms of their task performance; (2) investigate the pathways of change during the learning of a new coordination pattern and (3) examine how the learner’s coordination patterns relate to those of experts in the longswing gymnastics skill. Continuous relative phase of hip and shoulder joint motions was examined for longswings performed by two groups of novices, successful (n = 4) and unsuccessful (n = 4) over five practice sessions, and two expert gymnasts. Principal component analysis showed that during longswing positions where least continuous relative phase variability occurred for expert gymnasts, high variability distinguished the successful from the unsuccessful novice group. Continuous relative phase profiles of successful novices became more out-of-phase over practice and less similar to the closely in-phase coupling of the expert gymnasts. Collectively, the findings support the proposition that at the level in inter-joint coordination a technique emerges that facilitates successful performance but is not more like an expert’s movement coordination. This finding questions the appropriateness of inferring development towards a “gold champion” movement coordination.     

Learning from the experts: gaining insights into best practice during the acquisition of three novel motor skills

The amount and quality of practice predicts expertise, yet optimal conditions of practice have primarily been explored with novice learners. Ten expert musicians and ten novices practiced disc-throwing skills under self-regulated conditions. A third novice group practiced with the same schedule as the music experts (yoked). The groups did not differ in terms of the amount of contextual interference, only in terms of when in-practice interference was introduced. The music experts progressed from a more blocked to random schedule which was opposite to the novices. This resulted in more accurate performance in retention for the experts in comparison to both novice groups (self-scheduled and yoked). The music expert and yoked groups showed higher form scores than the novice self-scheduled group, which might be related to the greater frequency of augmented information for these groups. There was no evidence that non-task-domain experts choose a more random practice schedule than novices, but in accord with good practice principles, they gradually introduced high amounts of interference into their practice. This strategy was associated with less error in retention for the experts. Because the yoked group showed more error than the music experts, the advantage of this schedule was also performance dependent.