This paper studies the causes and consequences of in-season changes of the head-coach of association football teams. We exploit data from the highest level of Dutch professional football during 14 successive seasons. An in-season change of the head-coach depends on recent match results and the difference between actual results and expectations as measured using bookmaker data. We find that, after the head-coach has been replaced, teams perform better than before. However, the performance is also better than before for a control group of coach replacements that did not occur. From this we conclude that replacement of head-coaches does not improve team performance.