The Determinants of Soccer Player Substitutions

This paper analyzes the pattern of player substitutions during a soccer match using data from the Spanish First Division in the 2004—2005 season. We use an inverse Gaussian hazard model to analyze the first substitutions on each team taking place either at halftime or in the second half of the game. The results show that the most important factor explaining the timing of the first player substitutions on a team is the score as it stands prior to the substitution. Furthermore, defensive substitutions are made later in the match than offensive substitutions. We also found some evidence that home teams make more substitutions than visiting teams in the halftime interval.