In baseball, the head coach of a team is called the manager (or more formally, the field manager); this individual controls matters of team strategy on the field and team leadership. The manager sets the line-up and starting pitcher before each game as well as making substitutions throughout the game. How much control a manager takes in player strategy varies from one manager to another. Wikipedia
The definitive Wikipedia entry for Manager. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Manager_%28baseball%29