Section 4: Players & Officials
Players
Per ITF Rules of Tennis 2026, Rule 28 (Player Analysis), a match is played between two players (singles) or two teams of two players each (doubles). In doubles, each team is referred to as a "pair." One player on each side must serve at the start of each game, alternating between the members of the pair according to the rules of service rotation (Rule 14).
Players must be ready to play within the time limits set by the ITF or tournament referee. If a player is not ready to play within a reasonable time, the player may forfeit the match at the discretion of the referee.
The Chair Umpire
The chair umpire has overall responsibility for the conduct of the match and is the final authority on all matters of fact during play (ITF Rules of Tennis 2026, Appendix V). The chair umpire calls the score, calls lets, foot faults (when no line umpires are present), net cord, and all violations. The chair umpire may overrule a line umpire's call immediately if they are certain the call was incorrect (Rule 30, Case 3).
Line Umpires
Line umpires are assigned to monitor specific lines and make calls on balls landing in or out of their assigned lines. Their calls are final on matters of fact unless overruled by the chair umpire. In professional events using Electronic Line Calling (ELC) technology (e.g., Hawk-Eye Live), line umpires may not be present and all calls are generated electronically (ITF Rules of Tennis 2026, Appendix VI).
Foot Fault Judge
A foot fault judge may be appointed to monitor foot faults. In the absence of a foot fault judge, the chair umpire may call foot faults (Rule 18, Note).
The Referee
The tournament referee supervises the overall conduct of the tournament, has authority over scheduling and order of play, and may be consulted on questions of law (as opposed to questions of fact, which are determined by the chair umpire). The referee may remove a chair umpire during a match in exceptional circumstances.
Electronic Line Calling (ITF Rules 2026, Appendix VI)
The ITF has formally incorporated Electronic Line Calling Live (ELC Live) into the Rules as of 2023, with refinements in 2025 and 2026. Where ELC is operational, all line calls are made electronically and are final (no challenges or reviews permitted). The chair umpire retains authority over all other matters. If ELC malfunctions, the match reverts to traditional officiating.
Challenges (Hawk-Eye Review, Rule 30 & Appendix VI)
In tournaments not using ELC Live, electronic review (challenge) systems may be used. Each player receives three incorrect challenges per set (plus one additional incorrect challenge if a set goes to a tiebreak). A challenge is forfeited only if the call is confirmed as correct (i.e., the original call stands). If the challenge results in a reversal of the original call, the player retains the challenge.