Umpire (baseball)
In baseball, the umpire is the person charged with officiating the game, including beginning and ending the game, enforcing the rules of the game and the grounds, making judgment calls on plays, and meting out discipline. The term is often shortened to the colloquial form ump.Although games were often officiated by a sole umpire in the formative years of the sport, from the turn of the 20th century onward officiating has been commonly divided among several umpires, who form the umpiring crew. The home plate umpire (the only indispensable umpiring position), who is situated directly behind the catcher, is given the duty of calling balls and strikes on pitches as well as making safe/out calls at home plate. The first, second and third base umpires make safe/out calls at their respective bags while the first and third base umpires also make fair/foul calls on balls hit down the first and third baselines. Rulings on fair catches of batted balls are usually made by the umpire closest to the play. Other calls are typically the responsibility of the home plate umpire. (In the case of fewer available umpires, as is common in youth and community leagues, all responsibilities are bestowed upon the home plate umpire.)
Unlike referees in football, an umpire's call is final and cannot be reversed upon further inspection (unless there is disagreement amongst the umpiring crew).