The three and six-substitution rules in football: A preliminary comparative analysis in quantitative replacing, game statistics, win rate and winning probability

Abstract Aims: The present study aimed to analyze the effects of the 3- and 6-substitution rule and qualification round on substitution pattern, game statistics, win rate, and winning probability in Brazil's largest U-20 football tournament. Methods: We analyzed 1,339 matches from the São Paulo Junior Football Cup implementing a before-after design considering 6 years (three seasons for 3-subs and three for 6-subs). Results: Approximately 31% of teams used the total number of replacements of 6-subs with the same substitution pattern between rounds. The win rate for both substitution rules was approximately 79% (OR = 3.10, 95%CI [2.18, 4.51]) with a small reduced magnitude (approximately 5%) in 6-subs knockout games. Logistic regression analysis showed that the 6-subs regulation tournament predicted a reduced probability (-12%) of a match ending with a win in the knockout round. There were 6-subs knockout effects (p