…if Willie Mays played for your baseball team would you promote him to manager? True, he delivers more than his teammates, and he is one of the best players of all time, but a player of that caliber should be left where he can do the most good: smacking balls out of the park. Moving him into manager not only reduces his direct contribution to the team, but is done under the assumption that he has a clue how to manage his fellow players, instead of what he’s obviously demonstrated he can do: hit a baseball like few people in history have.

Rob Walling from his excellent blog.