A multilevel hypernetworks approach to capture meso-level synchronisation processes in football.

Understanding team behaviours in sports performance requires understanding the interdependencies established between their levels of complexity (micro-meso-macro). Previously, most studies examined interactions emerging at micro- and macro-levels, thus neglecting those emerging at a meso-level (reveals connections between player and team levels, depicted by the emergence of coordination in specific sub-groups of players-simplices during performance). We addressed this issue using the multilevel hypernetworks approach, adopting a cluster-phase method, to record player-simplice synchronies in two performance conditions where the number, size and location of goals were manipulated (first-condition: 6 × 6 + 4 mini-goals; second-condition: Gk + 6 × 6 + Gk). We investigated meso-level coordination tendencies, as a function of ball-possession (attacking/defending), field-direction (longitudinal/lateral) and teams (Team A/Team B). Generally, large synergistic relations and more stable patterns were observed in the longitudinal direction of the field than the lateral direction for both teams, and for both game phases in the first condition. The second condition displayed higher synchronies and more stable patterns in the lateral direction than the longitudinal plane for both teams, and for both game phases. Results suggest: (i) usefulness of hypernetworks in assessing synchronisation of teams at a meso-level; (ii) coaches may consider manipulating these task constraints to develop levels of local synchronies within teams.

Influence of Situational Variables, Team Formation, and Playing Position on Match Running Performance and Social Network Analysis in Brazilian Professional Soccer Players.

Aquino, R, Carling, C, Palucci Vieira, LH, Martins, G, Jabor, G, Machado, J, Santiago, P, Garganta, J, and Puggina, E. Influence of situational variables, team formation, and playing position on match running performance and social network analysis of brazilian professional soccer players. J Strength Cond Res 34(3): 808-817, 2020-The purpose of this study was to investigate the independent and interactive effects of situational variables, opposition team formation, and playing position on running performance and network analysis in Brazilian professional soccer players (n = 22). Global positioning system technology was used to determine total distance covered, mean speed, maximum running speed, and distance covered in 6 speed ranges. Social network analysis was used to assess interpersonal coordination (team interactions characterized as successful passes [n = 3,033] between teammates). Observations of match running performance (n = 129) and network analysis (n = 108) were obtained. The main results were: (a) no interactive effects between team formation and playing position were observed for running and network variables (unclear to possibly); (b) matches played at home or against "weaker" opponents presented greater running demands and individual/global metrics of network analysis (likely to almost certain); (c) match outcome demonstrated influence only for running performance; matches in which the reference team won resulted in higher values than in matches lost; (d) when the reference team competed in 1-4-4-2 formation, this resulted in greater running demands than 1-4-2-3-1 formation (likely to almost certain); (e) reduced values of running performance variables were reported in central defenders compared with other positions. Central/external midfielders reported greater closeness/betweenness centrality, outdegree, and eigenvector compared with central/external defenders and forwards (likely to almost certain). The results from this study provide practical information to potentially impact on physical, tactical, and technical training.

Influence of non-preferred foot technical training in reducing lower limbs functional asymmetry among young football players.

The functional asymmetry of the lower limbs has been regarded as a relevant factor of the performance of football players. We purposed to ascertain whether a specific technical training programme for the non-preferred foot has implications in the increasing utilisation rate of the respective member during the game. Young football players (n = 71) were randomly divided into experimental group (N = 35; 14.37 ± 1.94 years) and control group (N = 36; 14.50 ± 1.81 years). The study was developed into three stages: first, assessment of the index utilisation of both limbs during the game; second, application of a technical training programme that includes the drilling of specific motor skills exclusively directed to the non-preferred foot; and third, assessment of the new rate of both limbs' utilisation after the predefined six months. The main findings were: (1) the use of the non-preferred foot increased significantly with the technical training programme in the experimental group and remained constant in the control group; (2) the use of the preferred foot decreased significantly in the experimental group and remained similar in control group. We concluded that a systematic and specific technical training for the non-preferred foot increases its use and reduces functional asymmetry in game situation, consequently improving the player's performance.

Field dimension and skill level constrain team tactical behaviours in small-sided and conditioned games in football.

Abstract This study analysed the influence of field dimension and players' skill level on collective tactical behaviours during small-sided and conditioned games (SSCGs). Positioning and displacement data were collected using global positioning systems (15 Hz) during SSCGs (Gk+4 v. 4+Gk) played by two groups of participants (NLP- national-level and RLP-regional-level players) on different field dimensions (small: 36.8 × 23.8 m; intermediate: 47.3 × 30.6 and large: 57.8 × 37.4 m). Team tactical performance was assessed through established dynamic team variables (effective playing space, playing length per width ratio and team separateness) and nonlinear signal processing techniques (sample entropy of distances to nearest opponents and the teams' centroids' mutual information). Results showed that the effective playing space and team separateness increased significantly with pitch size regardless of participant skill level (P < 0.001, η2 = 0.78 and P < 0.001, η2 = 0.65, respectively). Playing length per width ratio increased with pitch size for the NLP but was maintained at a relatively constant level by RLP across treatments indicating different playing shapes. There was significantly more irregularity in distances to nearest opponents for the NLP in small (P = 0.003) and intermediate fields (P = 0.01). Findings suggest that tactical behaviours in SSCGs are constrained by field size and skill level, which need to be considered by coaches when designing training practices.

The Effects of Physiological Demands on Visual Search Behaviours During 2 vs. 1 + GK Game Situations in Football: An in-situ Approach.

We examined the effect of physiological workload on gaze behaviour during defensive performance in 2 vs. 1 +goalkeeper game situations in football. Twenty-two players were assigned to either a high- or low-performing group based on a validated measure of tactical performance. A total of 12 game sequences (trials) were presented under high- and low-workload conditions. At the end of each sequence, participants were asked to indicate their perceived exertion using the Rating Scale of Mental Effort and the Borg Scale. The low- and high-workload conditions were defined when the players achieved 60 and 90% of their maximal heart rate, respectively, as per their performance in the Yo-Yo Intermittent Recovery Test. Visual search behaviours were recorded using Tobii Pro eye-movement registration glasses. Players reported higher rates of perceived exertion on the high- compared to low-workload condition. Participants in the low-performing group increased their average fixation duration and decreased the number of fixations and number of fixation locations from the low- to high-workload conditions. The low- and high-performing groups displayed different visual search strategies with regards the areas of interest fixated upon. Participants in the high-performing group focused on the SpaceFrontPlayer, followed by Ball, and AnotherOpponent. The low-performing group spent more time focusing on the SpaceFrontPlayer and SpacePlayer than Ball and AnotherOpponent. It appears that physiological workload and tactical expertise interact in constraining visual search behaviours in football players. Coaches and practitioners should consider ways to manipulate individual and task constraints while attending to the close interplay between physiological workload, visual behaviour, and tactical performance during practise.

Water Polo Offensive Methods after the 2018 FINA Rules Update.

Water polo is a team sport that has been suffering rule changes aiming for a more attractive game. Our goal was to unveil whether different offensive playing styles or methods were adopted by elite national teams from Eastern Europe and from other world countries after the new rules framework was applied at the 2019 FINA World Championship. Additionally, we questioned whether those rules induced a more dynamic game. A total of 648 offensive sequences from games contested by the top-six ranked national squads were analysed. Descriptive statistics, parametric and nonparametric tests were computed, and the effect size was used. The eastern Europeans were the tallest (t (76) = −4.081; p < 0.001, d = 0.42) and the Hungarians were higher than Italians (p = 0.005, dz = −0.41). Offensive time length differed between teams (H (5) = 30.50, p < 0.001) with Serbia being the fastest (Mdn = 22 s). In successful attacks without extra time, Italy was quicker than Spain (17.5 vs. 25.0 s; p = 0.031, dz = −0.36) scoring 30% of their total goals under 20 s, while Australia up to 24% and Croatia, Hungary and Spain ≤ 16.0%. When power-play occurred, the teams' pass action was different (H (5) = 15.99, p < 0.007), with Italy performing more passes than counterparts, especially Serbia (Mdn = 13 vs. 9, respectively; p= 0.003, dz = 0.20) and with the exception of Hungary. Through fast play sequences, Italy, Serbia and Australia scored up to 33% of their goals, while Spain, Croatia, and Hungary scored ≤ 15%. The power-play contributed to ≥50% of teams' goals, except for Spain and Australia (48 and 45%, respectively). Playing styles commonly attributed to Eastern vs. non-Eastern Europeans and other worldwide national teams such as Australia were not confirmed. However, offensive trends were perceived and described for the first time, and some base guidelines were suggested to distinguish the static or positional vs. a more dynamic playing model. Rule changes did not seem to induce the expected effects on game dynamics.

Talent Development in Sport Requires Athlete Enrichment: Contemporary Insights from a Nonlinear Pedagogy and the Athletic Skills Model.

Traditional talent identification and development programs have sought to identify and select the most promising children as athletes of the future, to provide them with specialised training and preparation for expert performance in sport from an early age. Traditional models of talent identification and development tend to be linear, emphasising the numbers of hours spent in specialised training. However, major concerns have been raised by evidence emerging on psycho-emotional and physical issues with early specialisation programmes, and negative associations with wellbeing and mental health. More contemporary models of talent development emphasise a deep integration of specialised training with more general enrichment of athleticism. This integrative process enhances self-regulation processes of perception and action, as well as emotional control and social interactions, all of which underpin sports performance at elite and sub-elite levels. Here, we discuss insights and principles of contemporary models of pedagogy, such as Nonlinear Pedagogy (NLP) and the Athletic Skills Model (ASM), which offer valuable frameworks for talent development. We conclude by considering implications of adopting such principles for developing athlete functionality in specific performance environments.

How do Elite Soccer Teams Perform to Ball Recovery? Effects of Tactical Modelling and Contextual Variables on the Defensive Patterns of Play.

Researchers in soccer match analysis have been using limited procedures to express the dynamics of the game and mainly focus on the attack. Therefore, the aims of this paper were to detect the successful teams' ball recovery defensive patterns of play and study the influence of tactical modelling, halves, match status, opponent quality and stage competition on those patterns. The sample consisted of 1323 situations of defensive ball possession of the semi-finalist teams from the 2014 FIFA World Cup play-offs, which was collected by a valid and reliable observational instrument (Soccer-Defence). The Kruskal-Wallis H, Mann-Whitney U, Chi-square, Z-, multinomial logistic regression tests and sequential analysis (p < .05; z > 1.96) were used accordingly to test the differences and associations among and within teams of tactical modelling, tactical-technical behaviours and contextual variables to ball recovery. We found that among teams ball recovery differed in duration; H(3) = 14.958, p = .002. Germany were more likely to perform ball recovery by the goalkeeper than Argentina (p = .04; OR = 0.47) or the Netherlands (p < .05; OR = 0.50). Nevertheless, Brazil was the least likely to concede a shot off goal. Teams facing lower-ranked opponents were 0.63 times less likely to perform ball recovery by interception (p <.001). Additionally, sequential analysis illustrated that teams varied between central and lateral high-pressure zones before ball recovery in lower zones of the field. Finally, coaches could use such findings to design training exercises, create their own style of play, and set strategies.

Water Polo Shooting Performance: Differences Between World Championship Winning, Drawing and Losing Teams.

Shooting performance of globally ranked winning, drawing and losing water polo teams was compared, and technical and tactical success indicators were identified. In total, 886 shots from a world championship final round were videotaped and teams were clustered for a performance evaluation (considering differences between game outcomes). Shooting speeds were assessed by a radar, with higher values observed at further distances from the goal than in the central area close to the goal (p ≤ 0.00, ES: 2.54). Shots tended to be more frequent from the central corridor, with ≤50% and >75% relative shot efficacy attained from field areas 3 and 6; winning teams obtained better results. Furthermore, winners had greater success than losers when shooting from field area 2 (p ≤ 0.04, ES: 1.13) and towards the goal zone 2 (p < 0.03, ES: 1.10). They also attained better efficacy regarding shots towards goal zone 1, had better efficacy on the part of centre-forwards (p ≤ 0.05, ES: 0.85-1.27), and were more effective regarding shots without a frontal defensive block. In addition, contingency analysis highlighted shots performed from field area 6, without a defensive block, toward the bottom left goal corner, and through man-up play as success indicators (all for p ≤ 0.005). We concluded that world-level winning teams homogeneously distributed their shot opportunities at the second offensive line with balanced efficacy, creating variability and uncertainty in their opponents' defensive action. Elite level players must be capable of interpreting game situations with intelligence and proper decision making. This information may be useful for improving teams performance.

A multilevel hypernetworks approach to capture properties of team synergies at higher complexity levels.

Previous work has sought to explain team coordination using insights from theories of synergy formation in collective systems. Under this theoretical rationale, players are conceptualised as independent degrees of freedom, whose interactions can become coupled to produce team synergies, guided by shared affordances. Previous conceptualisation from this perspective has identified key properties of synergies, the measurement of which can reveal important aspects of team dynamics. However, some team properties have been measured through implementation of a variety of methods, while others have only been loosely addressed. Here, we show how multilevel hypernetworks comprise an innovative methodological framework that can successfully capture key properties of synergies, clarifying conceptual issues concerning team collective behaviours based on team synergy formation. Therefore, this study investigated whether different synergy properties could be operationally related utilising hypernetworks. Thus, we constructed a multilevel model composed of three levels of analysis. Level N captured changes in tactical configurations of teams during competitive performance. While Team A changed from an initial 1-4-3-3 to a 1-4-4-2 tactical configuration, Team B altered the dynamics of the midfielders. At Level N + 1, the 2 vs. 1 (1 vs. 2) and 1 vs. 1 were the most frequently emerging simplices, both behind and ahead of the ball line for both competing teams. Level N + 2 allowed us to identify the prominent players (a6, a8, a12, a13) and their interactions, within and between simplices, before a goal was scored. These findings showed that different synergy properties can be assessed through hypernetworks, which can provide a coherent theoretical understanding of competitive team performance.

The Role of Hypernetworks as a Multilevel Methodology for Modelling and Understanding Dynamics of Team Sports Performance.

Despite its importance in many academic fields, traditional scientific methodologies struggle to cope with analysis of interactions in many complex adaptive systems, including team sports. Inherent features of such systems (e.g. emergent behaviours) require a more holistic approach to measurement and analysis for understanding system properties. Complexity sciences encompass a holistic approach to research on collective adaptive systems, which integrates concepts and tools from other theories and methods (e.g. ecological dynamics and social network analysis) to explain functioning of such systems in their natural environments. Multilevel networks and hypernetworks comprise novel and potent methodological tools for assessing team dynamics at more sophisticated levels of analysis, increasing their potential to impact on competitive performance in team sports. Here, we discuss how concepts and tools derived from studies of multilevel networks and hypernetworks have the potential for revealing key properties of sports teams as complex, adaptive social systems. This type of analysis can provide valuable information on team performance, which can be used by coaches, sport scientists and performance analysts for enhancing practice and training. We examine the relevance of network sciences, as a sub-discipline of complexity sciences, for studying the dynamics of relational structures of sports teams during practice and competition. Specifically, we explore the benefits of implementing multilevel networks, in contrast to traditional network techniques, highlighting future research possibilities. We conclude by recommending methods for enhancing the applicability of hypernetworks in analysing team dynamics at multiple levels.

Exploiting Bi-Directional Self-Organizing Tendencies in Team Sports: The Role of the Game Model and Tactical Principles of Play.

Research has revealed how inherent self-organizing tendencies in athletes and sports teams can be exploited to facilitate emergence of dynamical patterns in synergy formation in sports teams. Here, we discuss how game models, and associated tactical principles of play, may be implemented to constrain co-existing global-to-local and local-to-global self-organization tendencies in team sports players during training and performance. Understanding how to harness the continuous interplay between these co-existing, bi-directional, and coordination tendencies is key to shaping system behaviors in sports training. Training programs are traditionally dominated by designs, which shape the self-organizing tendencies of players and teams at a global-to-local scale by coaches imposing a tactical/strategical plan with associated tactical principles of play. Nevertheless, recent research suggests that performers also need to be provided with opportunities to explore self-organizing tendencies that emerge at the local-to-global scale in training. This directional tendency in synergy formation can be facilitated by players being given opportunities to actively explore different adaptive and innovative performance solutions, coherent with principles of play circumscribed in an overarching game model. Developing methods (coaching sessions rooted on principles of dynamical systems theory that foment the development of such local-to-global relations) to exploit the continuous interplay between these co-existing tendencies within sports teams may promote more effective and efficient athlete skill training programs, in addition to enhancing performance.

Changing Rules and Configurations During Soccer Small-Sided and Conditioned Games. How Does It Impact Teams' Tactical Behavior?

The present study aimed to investigate how team's tactical behavior varies within and between age categories in different Small-Sided and Conditioned Games' configurations and conditions. Twenty non-elite youth male soccer players (U15, n = 10, mean age = 13.5 ± 1.2 years; U17, n = 10, mean age = 16.3 ± 0.5 years) were selected. Thirty-six Small-Sided and Conditioned Games (SSCG) were played in both categories, namely three Representative SSCG (R-SSCG), three Maintaining Ball Possession Games (MBPG) and three Progression to Target Games (PTG) performed for each configuration (Gk+3vs3+Gk and Gk+4vs4+Gk). Teams' tactical behavior was analyzed based on simple and composite performance indicators, as well as through Lag Sequential Analysis. Rules manipulation and SSCG configurations influenced teams' tactical behavior on both categories, but in different ways. Teams composed by younger players presented greater difficulties in MBPG played in smaller games configuration, while Gk+4vs4+Gk configuration can be used to enhance teams' tactical performance of younger players in R-SSCG and MBPG conditions. Moreover, increasing rules manipulations appeared to negatively impact on teams' exploratory behavior. Therefore, practitioners should carefully manipulate key constraints to adapt task demands to players' age category and training session's goals in order to enhance tactical performance.

Effects of the Pitch Surface on Displacement of Youth Players During Soccer Match-Play.

The aim of this study was to analyze the effect of different pitch surfaces (artificial turf, natural turf and dirt field) on positioning and displacement of young soccer players (age: 13.4 ± 0.5 yrs; body height: 161.82 ± 7.52 cm; body mass: 50.79 ± 7.22 kg and playing experience: 3.5 ± 1.4 yrs). Data were collected using GPS units which allowed to calculate spatial distribution variability, assessed by measuring entropy of individual distribution maps (ShannEn). Ellipsoidal areas (m2) representing players' displacement on the pitch, centred on the average players' positional coordinates, were also calculated, with axes corresponding to the standard deviations of the displacement in the longitudinal and lateral directions. Analysis of variance (ANOVA) was used to evaluate differences between pitch surfaces and across players' positions. There was significant effect in positioning (η2 = 0.146; p < 0.001) and displacement (η2 = 0.063; p < 0.05) by the players between pitch surfaces. A dirt field condition induced an increase in the players' movement variability, while players' displacement was more restricted when playing on artificial turf. Also, there were significant effects on positioning (η2 = 0.496; p < 0.001) and displacement (η2 = 0.339; p < 0.001) across players' positions. Central midfielders presented the greatest movement variability and displacement while fullbacks showed the lowest variability. Subsequently, the results may contribute to implement strategies that optimise players' performance in different surface conditions.

Team Sports Performance Analysed Through the Lens of Social Network Theory: Implications for Research and Practice.

This paper discusses how social network analyses and graph theory can be implemented in team sports performance analyses to evaluate individual (micro) and collective (macro) performance data, and how to use this information for designing practice tasks. Moreover, we briefly outline possible limitations of social network studies and provide suggestions for future research. Instead of cataloguing discrete events or player actions, it has been argued that researchers need to consider the synergistic interpersonal processes emerging between teammates in competitive performance environments. Theoretical assumptions on team coordination prompted the emergence of innovative, theoretically driven methods for assessing collective team sport behaviours. Here, we contribute to this theoretical and practical debate by re-conceptualising sports teams as complex social networks. From this perspective, players are viewed as network nodes, connected through relevant information variables (e.g. a ball-passing action), sustaining complex patterns of interaction between teammates (e.g. a ball-passing network). Specialised tools and metrics related to graph theory could be applied to evaluate structural and topological properties of interpersonal interactions of teammates, complementing more traditional analysis methods. This innovative methodology moves beyond the use of common notation analysis methods, providing a richer understanding of the complexity of interpersonal interactions sustaining collective team sports performance. The proposed approach provides practical applications for coaches, performance analysts, practitioners and researchers by establishing social network analyses as a useful approach for capturing the emergent properties of interactions between players in sports teams.

Sports teams as complex adaptive systems: manipulating player numbers shapes behaviours during football small-sided games.

Small-sided and conditioned games (SSCGs) in sport have been modelled as complex adaptive systems. Research has shown that the relative space per player (RSP) formulated in SSCGs can impact on emergent tactical behaviours. In this study we adopted a systems orientation to analyse how different RSP values, obtained through manipulations of player numbers, influenced four measures of interpersonal coordination observed during performance in SSCGs. For this purpose we calculated positional data (GPS 15 Hz) from ten U-15 football players performing in three SSCGs varying in player numbers (3v3, 4v4 and 5v5). Key measures of SSCG system behaviours included values of (1) players' dispersion, (2) teams' separateness, (3) coupling strength and time delays between participants' emerging movements, respectively. Results showed that values of participants' dispersion increased, but the teams' separateness remained identical across treatments. Coupling strength and time delay also showed consistent values across SSCGs. These results exemplified how complex adaptive systems, like football teams, can harness inherent degeneracy to maintain similar team spatial-temporal relations with opponents through changes in inter-individual coordination modes (i.e., players' dispersion). The results imply that different team behaviours might emerge at different ratios of field dimension/player numbers. Therefore, sport pedagogists should carefully evaluate the effects of changing RSP in SSCGs as a way of promoting increased or decreased pressure on players.

Practice effects on intra-team synergies in football teams.

Developing synchronised player movements for fluent competitive match play is a common goal for coaches of team games. An ecological dynamics approach advocates that intra-team synchronization is governed by locally created information, which specifies shared affordances responsible for synergy formation. To verify this claim we evaluated coordination tendencies in two newly-formed teams of recreational players during association football practice games, weekly, for fifteen weeks (thirteen matches). We investigated practice effects on two central features of synergies in sports teams - dimensional compression and reciprocal compensation here captured through near in-phase modes of coordination and time delays between coupled players during forward and backwards movements on field while attacking and defending. Results verified that synergies were formed and dissolved rapidly as a result of the dynamic creation of informational properties, perceived as shared affordances among performers. Practising once a week led to small improvements in the readjustment delays between co-positioning team members, enabling faster regulation of coordinated team actions. Mean values of the number of player and team synergies displayed only limited improvements, possibly due to the timescales of practice. No relationship between improvements in dimensional compression and reciprocal compensation were found for number of shots, amount of ball possession and number of ball recoveries made. Findings open up new perspectives for monitoring team coordination processes in sport.

Comparing Tactical Behaviour of Soccer Players in 3 vs. 3 and 6 vs. 6 Small-Sided Games.

The present study aimed to compare players' tactical behaviour in 3 vs. 3 and 6 vs. 6 soccer small-sided games (SSGs). The sample comprised 3,482 tactical actions performed by 18 U-11 youth soccer players from a Portuguese club, in 3 vs. 3 and 6 vs. 6 SSGs. All participants played eight minutes in both situations and field size was adapted according to the number of players involved (30 m × 19.5 m for 3 vs. 3 and 60 m × 39 m for 6 vs. 6). The System of Tactical Assessment in Soccer (FUT-SAT) was used for data collection and analyses. Descriptive analysis was conducted to verify frequencies and percentages of the variables assessed. The chi-squared (χ(2)) test was performed to compare the frequencies of the variables between 3 vs. 3 and 6 vs. 6 SSGs and Standardized Residuals (e) were used to examine the influence of the frequency of one or more variables within 3 vs. 3 and 6 vs. 6 SSGs. Data treatment was performed through SPSS for Windows®, version 18.0. Results indicated that players displayed safer behaviours in 6 vs. 6 SSG and more aggressive behaviours in 3 vs. 3 SSG. Findings can aid coaches and teachers to develop different players' tactical skills according to the chosen SSG (3 vs. 3 or 6 vs. 6) form.

Visual search behaviours and verbal reports during film-based and in situ representative tasks in volleyball.

Several researchers have explored the processes underlying perceptual-cognitive expertise, mainly using film-based studies. However, few have compared the extent to which data from film-based settings differ from those obtained through in situ collection. This gap in the literature is a relevant concern, since scientific research is used to provide guidance for designing training programmes. In this paper, eye movement recording and verbal reports of thinking were combined to explore the processes underpinning skilled performance in a representative volleyball task involving both film-based and in situ data collection. Nine volleyball players performed as backcourt defenders while wearing an eye-tracking device and providing verbal reports of thinking after each sequence. A number of significant differences were observed between the data gathered under film-based and in situ conditions. Namely, in the in situ condition participants employed longer fixations (728.11 ± 129.27 ms) than in the film condition (659.57 ± 178.06 ms), and there were differences in the nature of the fixation locations. With respect to verbal reports, participants exhibited superior level of sophistication in the in situ condition (2.57 ± 0.50 vs. 2.30 ± 0.84 in the film condition), while denoting a greater concern with the opponents under this condition (1.00 ± 0.73) than in the film condition (0.59 ± 0.60). These differences emerged despite task design and constraints being highly similar. No differences were apparent in the number of gaze fixations and fixation locations across conditions or in the number of verbalised condition concepts. Although exploratory, our data suggest that the mechanisms underpinning skilled decision-making in sports differ between film-based and in situ conditions.

Numerical relations and skill level constrain co-adaptive behaviors of agents in sports teams.

Similar to other complex systems in nature (e.g., a hunting pack, flocks of birds), sports teams have been modeled as social neurobiological systems in which interpersonal coordination tendencies of agents underpin team swarming behaviors. Swarming is seen as the result of agent co-adaptation to ecological constraints of performance environments by collectively perceiving specific possibilities for action (affordances for self and shared affordances). A major principle of invasion team sports assumed to promote effective performance is to outnumber the opposition (creation of numerical overloads) during different performance phases (attack and defense) in spatial regions adjacent to the ball. Such performance principles are assimilated by system agents through manipulation of numerical relations between teams during training in order to create artificially asymmetrical performance contexts to simulate overloaded and underloaded situations. Here we evaluated effects of different numerical relations differentiated by agent skill level, examining emergent inter-individual, intra- and inter-team coordination. Groups of association football players (national--NLP and regional-level--RLP) participated in small-sided and conditioned games in which numerical relations between system agents were manipulated (5v5, 5v4 and 5v3). Typical grouping tendencies in sports teams (major ranges, stretch indices, distances of team centers to goals and distances between the teams' opposing line-forces in specific team sectors) were recorded by plotting positional coordinates of individual agents through continuous GPS tracking. Results showed that creation of numerical asymmetries during training constrained agents' individual dominant regions, the underloaded teams' compactness and each team's relative position on-field, as well as distances between specific team sectors. We also observed how skill level impacted individual and team coordination tendencies. Data revealed emergence of co-adaptive behaviors between interacting neurobiological social system agents in the context of sport performance. Such observations have broader implications for training design involving manipulations of numerical relations between interacting members of social collectives.