In a round robin tournament, it is often believed that each team has an effect on its opponent which carries over to the next game of that opponent. Indeed, if team C plays against team A, and subsequently against team B, C's performance against B can be affected by A, and we say
that team B receives a carry-over effect from A. For instance, if team A is a very strong team, then team C could be exhausted and discouraged after this game, which could benefit its next opponent, team B. Clearly, any schedule will lead to carry-over effects. In this work, we develop an approach to measure whether carry-over effects have an influence on the outcome of football matches. We apply this method on the highest division in Belgium, using data from over 30 seasons. We find that there is no evidence to support the claim that carry-over effects affect the results.