Official (tennis) - Chair Umpire

The chair umpire is the final authority on all questions of fact during the match. Questions of fact include whether or not a ball was in, the calling of a service let or the calling of a foot-fault. In matches where line umpires are also assigned, the chair umpire has the right to overrule if they are sure that a clear mistake has been made. The chair umpire is often situated in a tall chair at the center of the court, behind a net post. The players' benches are to either side of the chair. From this position, the chair umpire calls the score of the match to the players and spectators between points. At the conclusion of a point, game, or set, the chair umpire times the players to ensure they follow ITF regulations on pace of play. The chair umpire is responsible for completing a scorecard, the official historical record of the match.