Authority

All players, coaches, managers, field or club staff, journalists, spectators or other persons on the field must follow the umpire's directions. The umpire oversees all these people and ensures that they act in a sportsmanlike manner and follow the official rules of the sport.

Ejection

The umpire can disqualify any players, coaches or managers for acting in an unsportsmanlike way or for using profanity. The umpire also can also eject disqualified players, coaches or managers from the field. The umpire can eject any grounds crew members, journalists or spectators from the field at any time if necessary.

Disputed Decisions

Many decisions that the umpire makes--such as calling a ball fair or foul, a runner safe or out, or a pitch a strike or a ball--require personal judgment. Though players, coaches or managers might disagree with the umpire's judgment, they must accept the umpire's decision as final.
 

Umpire-In-Chief

If a game has only one umpire, that umpire takes responsibility for managing all rules and conduct decisions. If a game has more than one umpire, one umpire takes the role of umpire-in-chief. The umpire-in-chief must stand behind the catcher. His responsibilities include calling and counting pitches as balls or strikes, calling batted balls fair or foul, making all calls regarding the batter and making all calls not specifically designated as field umpire responsibilities.

Field Umpires

If a game has more than one umpire, one umpire is the umpire-in-chief, and the others are field umpires. Field umpires stand on the playing field in a location that gives them the best view of the bases and the best ability to make rules calls. The field umpires' responsibilities include making all calls regarding the bases and the runners as well as assisting the umpire-in-chief on other rules calls.