The goal judge determines whether a player has scored a goal by watching to see if the puck has crossed the goal line completely. They act only in an advisory role; the referee has the sole authority to award goals, and thus can override the opinion of the goal judge.
One goal judge is positioned outside the rink directly behind each goal net. For arenas so equipped, the goal judge turns on a red light behind the goal to signal a score. The red light (and the green light which is mounted next to it) are hooked up to the game clock: when the clock is stopped or the green light is turned on when the game clock reads 00.0, the red light cannot be turned on. Joe Louis Arena in Detroit is the only arena in the league which uses a blue light to signal the end of the period.
In games governed by the IIHF, goal judges wear the same black-and-white striped shirts as on-ice officials.[7] This is not the case for goal judges in North America for games under different hockey codes.
In 2006, the NHL began experimenting with goal judges in higher seats (most commonly the press box, a catwalk or the lower section of the upper deck) with wireless signals. The idea was to allow teams to sell the lower seats, but also to give officials a better view of the action as to be able to reject goals if violations (illegally kicked in, player in the crease, offside) took place. As of 2010, all teams except for Boston (where TD Garden is used for amateur hockey also, most notably the Beanpot), Florida and Montreal locate goal judges in higher seats. In Vancouver and Nashville, one of the two goal judges is directly behind the net.
Goal judges were first used around 1877 in Montreal, and were initially called umpires.[8]