Does uniform color affect offside in association football?

Abstract

AbstractPast research has documented an impact of sportswear color on performance and referees' judgments in combat and team sports. Amongst other things, it was argued that these effects may arise from differences in visibility. In this regard, the current study was aimed at questioning the impact of uniform color on offside judgments in association football. We analyzed the number of offside judgments for 1530 matches from the first and second division of the football league in Germany and recorded the color of shirts, shorts and stockings for both teams. Data analyses revealed that attacking teams wearing black shirts and black stockings were accompanied by fewer offside decisions. In contrast, defending teams wearing black or green kits were accompanied by increased offside judgments against the opposing teams. Thus, it seems that black and green kits yielded favourable offside judgments. Regarding the low color contrast with green uniforms on a green lawn and the lower detection rate of dark colors the results suggest that green and black kits are less visible, which may impede players' visual detection. The results emphasise the importance of analyzing the role of uniform color in the context of offside decisions to ensure fair play and equal opportunities of winning.