Changing managers is often one of the first reactions to unsatisfactory team performance in professional football. But how responsible are managers for team performance? This paper uses data from the Bundesliga seasons 08/09 until 12/13 in order to investigate whether and why managers have an impact on team performance. It was found that while most managers do not affect results much, a small group actually improves team performance significantly. Further, it was found that managers who trained a club abroad before performed worse than their colleagues who spent their entire career in Germany.