An umpire in field hockey is a person with the authority to make decisions on a hockey pitch in accordance with the rules of the game. Each match is controlled by two such umpires. In theory they are responsible for decisions taken on their respective half of the field, but practically they "control' on either diagonal half of the field. In many higher-level events, a "reserve umpire" is appointed in addition to the two "field umpires" to act as a back-up in the event of injury or other issue preventing a field umpire from commencing or continuing a match. In World-Level competitions, a video umpire is also appointed in addition to the field and reserve umpires.