Dynamic-system analysis of opponent relationships in collective actions in soccer.

The aim of this study was to examine the contribution of the systemic approach to the analysis of play in team sports. We first focus on the theory of dynamical systems and consider the interactions between the main variables of the different components of systems and subsystems in soccer. In team sports, these variables represent fluctuating conditions, which momentarily constrain the organization of action for the players. Thus changes in the momentary configuration of the game have to be examined in the light of previous configurations, the outline of the defensive strategy and the tactical choices involved. To study this problem, we analyse the antecedents of goals in soccer. A procedure is proposed which analyses transitions between configurations of play, thus allowing time to be taken into consideration when studying the evolution of a match. To illustrate the use and benefit of the analytic procedure, two goals are described in terms of dynamic configurations of play and opportunity of choices made by attackers.