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 (SSG) format against two different teams changing the number of opponents (3, 5 & 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) x 360s data vectors. Using a soft-assembled hierarchy model by means of two statistical analyses: a Hierarchical Principal Components Analysis (HPCA) 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.