Keeping the Goal Safe! Measuring Synergistic Behavior Within a Defensive Unit of a Football Team

In team sports, teammates form functional synergies to outperform the opposition. Evidence suggests that synchronization among defenders is linked to successful outcomes. This study aimed to explore what mediates the formation of interpersonal synergies in a football defensive unit during both successful and unsuccessful defensive plays. Using the Uncontrolled Manifold (UCM) hypothesis, we analyzed 60 successful and 34 unsuccessful defensive sequences from five competitive matches. We examined two performance variables: the defensive set’s average position (Centroid) and its structure (Stretch Index). These variables were assumed to be stabilized by individual adjustments in players’ running line velocities. Interestingly, successful defensive outcomes were associated with lower UCM values, indicating that players’ velocity adjustments contributed less to stabilizing the defensive set’s position or structure. This suggests that success may rely more on effectively managing velocity variability between players rather than minimizing it. Overall, defensive synergies were more often formed to maintain the structure (Stretch Index) than the geographical position (Centroid) of the unit. Additionally, when the defense succeeded, the synergy strength was lower than during unsuccessful attempts. This implies that successful defense may result from flexible coordination rather than rigid control.