Linespersons

Linespersons are officials responsible for judging calls related to the boundary lines of a playing area. They are employed across several sports and may be referred to as line officials, line judges, or assistant referees depending on the sport and era. Their primary duty is to determine whether balls or players have stayed inside or crossed defined lines, and to signal line-related decisions to the main official or the scoreboard. In some sports, linespersons also handle sport-specific line duties such as offsides, boundary touches, or throw-ins.

In tennis, linespersons position themselves around the court and call balls in or out, reporting to the chair umpire who has final authority on the correct call. In association football, the traditional term linesman has given way in many contexts to assistant referees who operate along the touchlines, signaling offsides and assisting with other incidents, while communicating with the central referee. In ice hockey, linespersons patrol the rink’s sides to enforce offsides and icing and to conduct certain stoppages in play, typically under the guidance of the on-ice officials.

Training and credentialing for linespersons generally emphasize rule knowledge, positioning, rapid decision-making, and physical fitness. Officials are often certified by leagues or governing bodies and required to maintain proficiency through regular testing and continued education. Technological advances, including video replay and electronic line-calling systems in some sports, can supplement or, in rare cases, supersede human line calls.

Overall, linespersons play a specialized, evidence-based role in enforcing line-related rules, contributing to game flow, fairness, and officiating standards across multiple sports.