linejudgment

Line judgment is the process by which sports officials determine whether a ball or object has crossed a boundary line or touched a specified line, thereby deciding the outcome of a play. It covers calls such as in-bounds versus out-of-bounds, fair versus foul, and whether a ball crossed a goal line or boundary marker. Line judgment relies primarily on visual perception by officials positioned along or near the playing area, such as line judges, line umpires, or officials responsible for specific lines.

In many sports, multiple officials collaborate to produce a coherent line judgment. Line judges may be stationed along sidelines, baselines, or goal lines and communicate with the head referee or umpire. The accuracy of these calls can be affected by speed of play, distance, angle, lighting, weather, and player movement. When calls are disputed, officials may confer or defer to review processes provided by the sport’s rules.

Technological aids have been introduced to support line judgment in several sports. Instant replay, ball-tracking systems, and goal-line technology are used to improve accuracy and reduce contentious incidents. Tennis, cricket, and soccer have notably integrated such technologies, while other sports continue to balance human judgment with select replay options.

The concept of line judgment is central to the fairness and flow of many games. It influences strategic decisions, coaching challenges, and ongoing discussions about officiating standards. Related terms include officiating, umpiring, and sport-specific line calls or technologies designed to improve accuracy.