Change-of-direction profiles in elite football: Evidence from the 2022 FIFA World Cup.

Abstract

This study characterised change-of-direction (COD) profiles of outfield players during the 2022 FIFA World Cup and compared the outputs of two optical tracking-based detection algorithms applied to the same dataset. Optical tracking data from all 64 matches of the 2022 FIFA World Cup were processed to detect COD events for 1,351 full-match outfield player-game observations (≥45 min) using two established algorithms: the jerk-based method of Kai et al. (2021; Method 1) and the curvilinear locomotion method of Granero-Gil et al. (2020; Method 2). Method 1 detected 15.4 ± 6.7 CODs per player-game (mean angle 38.6 ± 15.1°), while Method 2 detected 111.1 ± 43.6 per player-game (mean angle 72.2 ± 4.8°), a 7.2-fold difference. Agreement was poor to very poor across all variables (ICC: −0.75 to −0.20). COD frequency declined significantly from the first to second half for both methods (M1: −28.8%, r = 0.35; M2: −25.0%, r = 0.48). Positional effects were substantial for Method 2 (η² = 0.191) but small for Method 1 (η² = 0.024). Tournament stage had negligible influence on COD output. The two detection methods yield substantially different COD profiles and cannot be considered interchangeable, reflecting the fact that they operationalise distinct movement constructs. Method 1 captures discrete acceleration-driven cutting events, whereas Method 2 captures continuous curvilinear locomotion. Positional differences are evident, with central midfielders demonstrating a distinctively high curvilinear COD count. COD frequency declined substantially from the first to second half across both methods; Method 1 mean angle increased modestly in the second half, consistent with fatigue selectively eliminating lower-intensity directional adjustments, though tactical and contextual explanations cannot be excluded. These findings highlight the importance of method standardisation and construct transparency in COD research and provide reference values for elite international tournament play.