Roles of a "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 insure they follow ITF regulations on pace of play. The chair umpire is responsible for completing a scorecard, the official historical record of the match.

Other than calling and keeping score, the chair umpire is entitled to assess penalties for the violation of the player's code of conduct. The code of conduct as well as penalties vary by competition authority. In the United States under the USTA Point Penalty System, the chair umpire can penalize players for delay, visible or audible profanity, racket and ball abuse, verbal or physical abuse of a player or umpire, and other unsportsmanlike conduct.