Angel Ric

Timescales for exploratory tactical behaviour in football small-sided games

ABSTRACT The aim of this study was to identify the dynamics of tactical behaviour emerging on different timescales in football small-sided games and to quantify short- and long-term exploratory behaviour according to the number of opponents. Two teams of four professional male footballers played small-sided games against two different teams with a variable number of opponents (3, 5 and 7). Data were collected using a combination of systematic observation and a non-differential global positioning system (15 Hz). The temporal diversity and structural flexibility of the players were determined by calculating the dynamic overlap order parameter q, entropy and trapping strength. Analysis of the exploratory dynamics revealed two different timescales, forming a different metastable landscape of action for each constraint. Fast dynamics lasted on average a few seconds and consisted of changes in tactical patterns. The long timescale corresponded to the shared tasks of offence and defence lasting tens of seconds. The players’ tactical diversity decreased with an increasing number of opponents, especially in defence. Manipulating numerical imbalance is likely to promote changes in the diversity, unpredictability and flexibility of tactical solutions. The fact that the temporally nested structure of constraints shaped the emergence of tactical behaviour provides a new rationale for practice task design. The manipulation of numerical imbalance on the timescale of a few tens of seconds, on which the exploratory behaviour of players saturates, may help coaches to optimise the exploratory efficiency of the small-sided games.

Emergence of exploratory, technical and tactical behavior in small-sided soccer games when manipulating the number of teammates and opponents

The effects that different constraints have on the exploratory behavior, measured by the variety and quantity of different responses within a game situation, is of the utmost importance for successful performance in team sports. The aim of this study was to determine how the number of teammates and opponents affects the exploratory behavior of both professional and amateur players in small-sided soccer games. Twenty-two professional (age 25.6 ± 4.9 years) and 22 amateur (age 23.1 ± 0.7 years) male soccer players played three small-sided game formats (4 vs. 3, 4 vs. 5, and 4 vs. 7). These trials were video-recorded and a systematic observation instrument was used to notate the actions, which were subsequently analyzed by means of a principal component analysis and the dynamic overlap order parameter (measure to identify the rate and breadth of exploratory behavior on different time scales). Results revealed that a higher the number of opponents required for more frequent ball controls. Moreover, with a higher number of teammates, there were more defensive actions focused on protecting the goal, with more players balancing. In relation to attack, an increase in the number of opponents produced a decrease in passing, driving and controlling actions, while an increase in the number of teammates led to more time being spent in attacking situations. A numerical advantage led to less exploratory behavior, an effect that was especially clear when playing within a team of seven players against four opponents. All teams showed strong effects of the number of teammates on the exploratory behavior when comparing 5 vs 7 or 3 vs 7 teammates. These results seem to be independent of the players’ level.

Soft-assembled Multilevel Dynamics of Tactical Behaviors in Soccer

This study aimed to identify the tactical patterns and the timescales of variables during a soccer match, allowing understanding the multilevel organization of tactical behaviors, and to determine the similarity of patterns performed by different groups of teammates during the first and second halves. Positional data from 20 professional male soccer players from the same team were collected using high frequency global positioning systems (5 Hz). Twenty-nine categories of tactical behaviors were determined from eight positioning-derived variables creating multivariate binary (Boolean) time-series matrices. Hierarchical principal component analysis (PCA) was used to identify the multilevel structure of tactical behaviors. The sequential reduction of each set level of principal components revealed a sole principal component as the slowest collective variable, forming the global basin of attraction of tactical patterns during each half of the match. In addition, the mean dwell time of each positioning-derived variable helped to understand the multilevel organization of collective tactical behavior during a soccer match. This approach warrants further investigations to analyze the influence of task constraints on the emergence of tactical behavior. Furthermore, PCA can help coaches to design representative training tasks according to those tactical patterns captured during match competitions and to compare them depending on situational variables.

Dynamics of tactical behaviour in association football when manipulating players' space of interaction

The analysis of positional data in association football allows the spatial distribution of players during matches to be described in order to improve the understanding of tactical-related constraints on the behavioural dynamics of players. The aim of this study was to identify how players’ spatial restrictions affected the exploratory tactical behaviour and constrained the perceptual-motor workspace of players in possession of the ball, as well as inter-player passing interactions. Nineteen professional outfield male players were divided into two teams of 10 and 9 players, respectively. The game was played under three spatial constraints: a) players were not allowed to move out of their allocated zones, except for the player in possession of the ball; b) players were allowed to move to an adjacent zone, and; c) non-specific spatial constraints. Positional data was captured using a 5 Hz interpolated GPS tracking system and used to define the configuration states of players for each second in time. The configuration state comprised 37 categories derived from tactical actions, distance from the nearest opponent, distance from the target and movement speed. Notational analysis of players in possession of the ball allowed the mean time of ball possession and the probabilities of passing the ball between players to be calculated. The results revealed that the players’ long-term exploratory behaviour decreased and their short-term exploration increased when restricting their space of interaction. Relaxing players’ positional constraints seemed to increase the speed of ball flow dynamics. Allowing players to move to an adjacent sub-area increased the probabilities of interaction with the full-back during play build-up. The instability of the coordinative state defined by being free from opponents when players had the ball possession was an invariant feature under all three task constraints. By allowing players to move to adjacent sub-areas, the coordinative state became highly unstable when the distance from the target decreased. Ball location relative to the scoring zone and interpersonal distance constitute key environmental information that constrains the players’ coordinative behaviour. Based on our results, dynamic overlap is presented as a good option to capture tactical performance. Moreover, the selected collective (i.e. relational) variables would allow coaches to identify the effects of training drills on teams and players’ behaviour. More research is needed considering these type variables to understand how the manipulation of constraints induce a more stable or flexible dynamical structure of tactical behaviour.

Emerging Collective Shared Behaviors from Individual Exploration in Football Small-Sided Games

The aim of this study was to identify the soft-assembled exploratory hierarchical dynamics of tactical behavior under specific task constraints manipulations. Two teams of four professional male footballers played in small-sided games format against two different teams changing the number of opponents (3, 5, and 7). Resulting trials were analyzed by a combination of systematic observation and a non-differential global positioning system (15 Hz). Tactical patterns of each player formed 37 (4D categories) ×360 s data vectors. Using a soft-assembled hierarchy model by means of two statistical analyses: a hierarchical principal component analysis and the calculation of dynamic overlap order parameter q, we determined the hierarchical structure of the potential landscape of the team players and its dynamic properties. The sequential reduction of each set level of principal components (PCs) revealed one PC as the slowest collective variable forming the global basin of attraction of tactical patterns. The dynamic overlap showed the interaction of two separate time scales. The short time scale lasted a few seconds and corresponded to short-lived emergent task solutions. The long time scale corresponded to the shared tasks of offence and defense lasting tens of seconds. The stationary overlap of the exploratory dynamics showed the decrease on behavioral diversity with an increasing number of opposing players. The temporally nested structure of constraints shaped the emergence of tactical behavior providing a new rationale for practice task design.

Emerging Dance Movements Under Ecological Constraints in Contact Improvisation Dancers with Different Background

Contact improvisation dance generates different ways of moving and a varied use of motor creativity depending on the constraints acting on the system. The aim of this study was to analyze the softly assembled dynamics and the emergency of different dance movements of different couples of improvisers with different background dancing under specific task constraints manipulations. One couple of contemporary dancers and one couple of novices were video-recorded while dancing with different constraints: (1) try to maintain both pelvis as close as possible and (2) try to maintain body contact but both pelvis as far as possible. Resulting trials were sequentially observed using an observational instrument and the data obtained were analyzed using a soft-assembled hierarchy model analysis: a principal component analysis, calculation of Hamming distances (HD) between binary vectors and the calculation of dynamic overlap order parameter q to determine the structure of the potential landscape of the dancer and its dynamic properties. Results showed a higher exploratory behavior when the system was constrained in a specific way, but also constraints forced the system to train specific techniques or movement patterns. Configurations were modified depending on the constraint in the couple of contemporary dancers, but the novices were less influenced.