Set similarity modulates object tracking in dynamic environments

Based on the observation that sports teams rely on colored jerseys to define group membership, we examined how grouping by similarity affected observers’ abilities to track a “ball” target passed between 20 colored circle “players” divided into two color “teams” of 10 players each, or five color teams of four players each. Observers were more accurate and exerted less effort (indexed by pupil diameter) when their task was to count the number of times any player gained possession of the ball versus when they had to count only the possessions by a given color team, especially when counting the possessions of one team when players were grouped into fewer teams of more individual members each. Overall, results confirm previous reports of costs for segregating a larger set into smaller subsets and suggest that grouping by similarity facilitates processing at the set level.     

How perceiving additional targets modifies teams’ tactical behavior during football small-sided games

This study aimed to measure how the change on targets information modifies teams’ tactical behavior during football small-sided games. 20 male senior professional players divided in 4 teams of 5 players participated in the study. Each team played two small-sided games, one with 2 official targets with goalkeeper and one with 6 small targets. Positional data of each player were recorded using a 15 Hz portable GPS. The distance between the centers of gravity (CG) of both team, the stretch index and the relative stretch index were measured and differences accessed via standardized differences, coefficient intervals and meta-analysis procedures. A moderate increase on the distance between the CG of each team and a small decrease on the stretch index and on the relative stretch index from 2 targets to the 6 targets games was observed. It was also identified that pitch location affected the interaction between teams. When the game was played in lateral corridors or defensive sectors, the differences between game conditions increased. Emphasizing the information for attacking team to shoot at goal, by manipulating the number of targets constrained tactical behavior of teams. The amplification of specific information on small-sided games can help coaches to promote players and teams’ emergent adapted behaviors.     

Quantifying synergies in two-versus-one situations in team sports: An example from Rugby Union

Collective behaviors in team sports result in players forming interpersonal synergies that contribute to performance goals. Because of the huge amount of variables that continuously constrain players’ behavior during a game, the way that these synergies are formed remain unclear. Our aim was to quantify interpersonal synergies in the team sport of Rugby Union. For that purpose we used the Uncontrolled Manifold Hypothesis (UCM) to identify interpersonal synergies that are formed between ball carrier and support player in two-versus-one situations in Rugby Union. The inter-player angle close to the moment of the pass was used as a performance variable and players running lines velocities as task-relevant elements. Interpersonal synergies (UCM values above 1) were found in 19 out of 55 trials under analysis, which means that on 34% of the trials, the players’ running line velocities contribute to stabilizing the inter-player angle close the moment of the pass. The strength of the synergy fluctuates over time indicating the existence of a location effect during attack phases in Rugby Union. UCM analysis shows considerable promise as a performance analysis tool in team sports to discriminate between skilled sub-groups of players.     

Interpersonal coordination and ball dynamics in futsal (indoor football)

Here, we report an investigation of the patterned movement behavior of players for a specific sub-phase of the game of futsal, namely when the goalkeeper for the attacking team is substituted with an extra outfield player. The movement trajectories of the ball and players were recorded in both lateral and longitudinal directions and investigated using relative phase analysis. Some differences in phase relations between different playing dyads were noted, indicating specificity of phase attractions, or otherwise, for certain players. In general terms, the defenders demonstrated strong in-phase attractions with the ball and with each other, whereas weaker phase attractions, indicated by increased relative phase variability, were observed for the attackers and ball, as well as between attackers themselves. These results demonstrate different coordination dynamics for the defending and attacking dyads, from which we interpret evidence for different playing sub-systems consistent with different team objectives linked together in an overarching game structure. In keeping with dynamical systems theory for complex systems, we view this sub-phase of futsal as being characterized by coordinated behavior patterns that emerge as a result of self-organizing processes. These dynamic patterns are generated within functional constraints, with players and teams exerting mutual influence on each other.     

Territorial gain dynamics regulates success in attacking sub-phases of team sports

Background and objective

Field invasion games, such as rugby union, can be conceptualised as dynamic social systems in which the agents continuously interact to contest ball possession and territorial gain. Accordingly, this study aimed to identify the collective system dynamics of rugby union phases-of-play near the try line by investigating whether ball displacement trajectory on the playing field provides insights on successful team performance.

Methods

Five rugby union matches were videotaped involving teams at a national league performance level. From these matches, 22 second phases-of-play were selected and digitized for analysis. The variable “distance gained” was investigated as a potential coordination variable describing functional coordination between players and teams. This variable concerned the distance between ball initial position and ball current position over time and was used to define the degree of territory gained by an attacking team.

Results

Analysis of distance gained dynamics in attacking sub-phases demonstrated the intermittent character of rugby union performers displacement trajectories on the playing field. Amplitude of ball movements was revealed as a distinguishing feature related to attacking effectiveness. Successful attacking phases displayed lower distances of positional retreat, with the maximum retreat distance achieved sooner in successful compared to unsuccessful phases-of-play. Autocorrelation and ApEn analyses suggested low system variability within time series data concerning both performance outcomes. However, evidence of less regularity and more complexity was found in unsuccessful phases-of-play.

Conclusion

Results suggested that distance gained dynamics manifests a characteristic collective behaviour pattern that captures the macroscopic functional order of multi-player attack–defence systems in team sports like rugby union.     

Role Asymmetry and Code Transmission in Signaling Games: An Experimental and Computational Investigation

In signaling games, a sender has private access to a state of affairs and uses a signal to inform a receiver about that state. If no common association of signals and states is initially available, sender and receiver must coordinate to develop one. How do players divide coordination labor? We show experimentally that, if players switch roles at each communication round, coordination labor is shared. However, in games with fixed roles, coordination labor is divided: Receivers adjust their mappings more frequently, whereas senders maintain the initial code, which is transmitted to receivers and becomes the common code. In a series of computer simulations, player and role asymmetry as observed experimentally were accounted for by a model in which the receiver in the first signaling round has a higher chance of adjusting its code than its partner. From this basic division of labor among players, certain properties of role asymmetry, in particular correlations with game complexity, are seen to follow.     

Effects of public posting,goal setting,and oral feedback on the skills of female soccer players

We evaluated the effects of public posting, goal setting, and oral feedback on the skills of 3 female high school soccer players during practice scrimmages. The dependent variables were the percentage of appropriate responses when the player (a) kept and maintained possession of the ball, (b) moved to an open position during a game restart (e.g., goal or corner kick), and (c) moved to an open position after passing the ball. We also assessed the extent to which changes in practice performances generalized to games. A social validity questionnaire was completed by both players and coaches to assess the acceptability of the intervention's goals, procedures, and outcomes. Results indicate that the intervention was effective in improving performances during practice scrimmages but produced limited generalization to game settings.     

Do not drop your gloves: “Winning” a fight in the National Hockey League does not improve chances to win the game

Sanctioned fighting has played an integral role in the National Hockey League (NHL) since its early days. Proponents argue that this practice helps teams win games. More specifically, they contend that when a player triumphs decisively in a fight, the outcome creates momentum or a spark for his teammates and thus increases his team’s odds of victory. We used on-line fans’ voting (validated by objective fight data) to assess fight outcome and demonstrated that “winning” the fight did not lead to winning the game when the score was tied. Additionally, in contrast with the “change in momentum” hypothesis, prevailing in a fight did not sway game outcome when the home or away team was one goal behind early enough in the game. Lastly, prevailing in a fight was not associated with scoring the next goal. We discuss the results in light of the strong conviction held by NHL players that fighting boosts momentum and explain possible mechanisms working to preserve this false belief.     

Division of labor as an emergent phenomenon of social coordination: The example of playing doubles-pong

In many daily situations, our behavior is coordinated with that of others. This study investigated this coordination in a doubles-pong task. In this task, two participants each controlled a paddle that could move laterally near the bottom of a shared computer screen. With their paddles, the players needed to block balls that moved down under an angle. In doing so, they needed to make sure that their paddles did not collide. A successful interception led to the ball bouncing back upwards. Importantly, all communication other than through vision of the shared screen was excluded. In the experiment, the initial position of the paddle of the right player was varied across trials. This allowed testing hypotheses regarding the use of a tacitly understood boundary to divide interception space. This boundary could be halfway the screen, or in the middle between the initial positions of the two paddles. These two hypotheses did not hold. As an alternative to planned division of labor, the behavioral patterns might emerge from continuous visual couplings of paddles and ball. This was tested with an action-based decision model that considered the rates of change of each player’s angle between the interception axis and the line connecting the ball and inner edge of the paddle. The model accounted for the observed patterns of behavior to a very large extent. This led to the conclusion that decisions of who would take the ball emerged from ongoing social coordination. Implications for social coordination in general are discussed.     

Perceived Coaching Behaviors and College Athletes' Intrinsic Motivation: A Test of Self-Determination Theory

We investigated whether a shared mental model is present in elite ice hockey and handball teams. In total, 231 male players participated in the study. Shared mental models were found to exist. Relationships between shared mental models and coaching efforts to develop a general training shared mental model and an opponent-specific model were explored. The relationship between role clarity and shared mental model, general training shared mental model, and opponent-specific model was positive. The shared mental model is a useful construct for analyzing elite team practice and coaching behavior. Coaches and sport psychologists should be aware that establishing a shared mental model in elite teams is essential in facilitating performance.     

Discriminative game-related statistics between basketball starters and nonstarters when related to team quality and game outcome

The aim of the present paper was to examine the differences in game-related statistics between basketball players who are selected for the starting five of the team (starters) and those who are not (nonstarters) when related to game outcome (winning and losing) and team quality (best teams, teams classified for the playoffs; and worst teams, teams who miss playoff classification). Archival data were gathered for all 2002-2003 regular season games from the Portuguese Professional League (N = 156). Discriminant analysis was used to identify the game-related statistics that differentiate between starters and nonstarters and interpreted by the examination of the structure coefficients (SC). When the best teams won the games, results described differences between starters and nonstarters with an emphasis on defensive rebounds (SC = .32), assists (SC = .32) and committed fouls (SC = -.68). When the worst teams won the games, results described differences between starters and nonstarters with an emphasis on 2-point field goals successful (SC = .47) and unsuccessful (SC = .48), defensive rebounds (SC =.39), successful free throws (SC =.32), and committed fouls (SC = -.55). An also important finding was that, in best teams, the nonstarters' performance was worse in the games that the team lost, whereas in worst teams, it was the starters' performance that was worse in the games that the team lost.     

Adaptive behaviours of attacking futsal teams to opposition defensive formations

This study evaluated tendencies towards flexibility/stability of coordinated behaviours in international futsal teams, considered as complex collective systems, according to changes in opposition defensive formations. Six games of two international futsal teams (Spain and Portugal) were selected for Social Network Analysis to capture the coordination tendencies that emerge in the tactical behaviours of players when performing against different defensive formations. Ball trajectories in each offensive pattern of play were notated in an adjacency matrix where each entry accounted for the linkages between 12 spatial field areas. Each offensive play was coded according to the defensive formation of an opposing team (i.e. conservative or risky formation). Results revealed similar network properties between teams when competing against more risky defensive formations, while notable differences were observed against conservative defences. Effect of defensive formation of opponents on macro network properties was observed in both the Portuguese and Spanish teams. At a meso-level, only the Spanish national team exhibited notable changes, suggesting a greater level of adaptability to unfolding performance events. The observed flexibility in tactical behaviours of the Spanish team appeared to express their greater expertise levels.     

Shared Expectations and Implicit Coordination in Tennis Doubles Teams

Very little of the existing research on team cognition has looked at sports teams. The purpose of this study was to extend previous research to the sports domain, and empirically test the relationship between one aspect of team cognition—shared expectations—and implicit coordination in 71 American tennis doubles teams. We tested a model hypothesizing a link between prior experience, shared expectations, and implicit coordination. Prior experience influenced implicit coordination directly, as well as through a positive relationship with shared expectations. The findings highlight the potential of using behavioral measures of team coordination in sport psychology.     

Information and the complementarity game

Complementarity games are explorative games between two players. The deterministic rules of the game are known to both players. The first player freely chooses among a finite number of states of the game but tells nobody of this decision. The second player accesses the game only by primitive, symbolic input‐output interfaces. The task of the second player is to find out the unknown state by input‐output experiments. The logic resulting from this scenario resembles‐ quantum logic in many aspects. It is the empirical logic of choice for virtual realities.     

Are Pre-Assembly Shared Work Experiences Useful for Temporary-Team Assembly Decisions? A Study of Olympic Ice Hockey Team Composition

The purpose of this study was to investigate if pre-assembly shared work experiences among temporary team members facilitate individual and team performance. Archival data from the 2014 Men’s Olympic Ice Hockey Tournament (12 teams, 25 players each) was used in the study. Measures of social network centrality were computed based on the pre-assembly shared work experiences among national team members derived from professional and amateur affiliations. These measures were used to predict objective individual and team performance criteria. Players’ closeness centrality scores, from pre-assembly shared work experience networks, positively predicted their goals, assists, and being involved in more positive than negative plays. Teams with less centralized pre-assembly shared work experience network structures tended to perform better than teams with more centralized pre-assembly shared work experience network structures. Temporary teams are commonly used by organizations to perform tasks that are specific, important, and of short duration. Because temporary teams have little time to develop the shared properties required for effective team functioning, assembly decisions are of paramount importance. The results from this study suggest that centrality measures derived from pre-assembly shared work experiences are useful to consider when assembling temporary teams. Few studies have investigated the impact of pre-assembly shared work experiences on individual and team performance. Using objective data, this study provides evidence that pre-assembly shared work experiences relate to individual and team performance in temporary teams, supporting the need for expanded research in this area.     

The experience of ego threat in the public arena: A study of air ball shots performance in collegiate basketball

Performance following ego threat has often been studied in the laboratory under conditions, which may limit external validity. In the current investigation, Men’s college basketball games were studied focusing on attempts at shot that completely missed the basket and are thus known colloquially as “air ball” shots (ABS). When an away player launches an ABS, the home crowd is likely to recite in unison an “air ball, air ball” chant (ABC) to single him out for a uniquely subpar performance. Similar poor performance by a home player is almost always ignored. An archival exploration showed that away players who shot an ABS had a lower success rate in the shot immediately after, as compared to home players launching an ABS, however, this difference was unrelated to ABC. Also, players with a better shooting ability were better able to deal with the debilitating effects. The results expand ego threat research and are discussed in the context of ego‐depletion and a model is proposed to predict performance quality in social context when the negative feedback is delivered by partisans and one’s knowledge of his skill level is known.     

Team history and choking under pressure in major soccer penalty shootouts

This study examined the links between historical team results and individual players' subsequent performances in a high-pressure real-world sport situation. Videos were obtained from all soccer penalty shootouts held in two major international tournaments (World Cup and European Championships) between 1976 and 2006 (n=260 players/309 kicks), and we controlled for team ability and country. The results showed that players on teams with preceding losses performed worse and generally took their shots more quickly than players on teams with preceding wins. These differences were also found with players who took no personal part in the preceding games. In conclusion, the results support the existence of historical dependency effects for performance on important and dramatic high-pressure tasks and they are in part consistent with a view of choking under pressure as a function of threatened egotism and self-regulation failure.     

The impact of cross-training on team effectiveness

The authors examined the role of cross-training in developing shared team-interaction mental models, coordination, and performance in a 2-experiment study using computer simulation methodology (for Experiment 1, N = 45 teams; for Experiment 2, N = 49 teams). Similar findings emerged across the 2 experiments. First, cross-training enhanced the development of shared team-interaction models. Second, coordination mediated the relationship between shared mental models and team performance. However, there was some inconsistency in the findings concerning the depth of cross-training necessary for improving shared mental models. Results are discussed in terms of the impact of different levels of cross-training on team effectiveness.     

Visual reaction time and high-speed ball games

Laboratory measures of visual reaction time suggest that some aspects of high-speed ball games such as cricket are 'impossible' because there is insufficient time for the player to respond to unpredictable movements of the ball. Given the success with which some people perform these supposedly impossible acts, it has been assumed by some commentators that laboratory measures of reaction time are not applicable to skilled performers. An analysis of high-speed film of international cricketers batting on a specially prepared pitch which produced unpredictable movement of the ball is reported, and it is shown that, when batting, highly skilled professional cricketers show reaction times of around 200 ms, times similar to those found in traditional laboratory studies. Furthermore, professional cricketers take roughly as long as casual players to pick up ball flight information from film of bowlers. These two sets of results suggest that the dramatic contrast between the ability of skilled and unskilled sportsmen to act on the basis of visual information does not lie in differences in the speed of operation of the perceptual system. It lies in the organisation of the motor system that uses the output of the perceptual system.