Empirical Evidence on the “Never Change a Winning Team” Heuristic

Abstract

"Never change a winning team" is a well-known heuristic that recommends not altering the composition of successful teams. Using game-level observations of the highest German soccer league over a period of seven seasons, we find that the number of changes in the starting line-up is significantly lower after wins than after losses, taking suspensions and unobserved team heterogeneity into account. We show that teams of coaches who follow the heuristic do not win significantly more often, and that coaches significantly decrease the number of changes in the starting line-up even after wins caused by the exogenous home field advantage. These results provide first suggestive evidence that coaches may be influenced by behavioural concerns when following the heuristic to not change winning teams. Summary"Never change a winning team" is a well-known heuristic that recommends not altering the composition of successful teams. Using game-level observations of the highest German soccer league over a period of seven seasons, we find that the number of changes in the starting line-up is significantly lower after wins than after losses, taking suspensions and unobserved team heterogeneity into account. We show that teams of coaches who follow the heuristic do not win significantly more often, and that coaches significantly decrease the number of changes in the starting line-up even after wins caused by the exogenous home field advantage. These results provide first suggestive evidence that coaches may be influenced by behavioural concerns when following the heuristic to not change winning teams.