Plus−minus (+/−, ±, plus/minus) is a sports statistic used to measure a player's impact on the game, represented by the difference between their team's total scoring versus their opponent's when the player is in the game. In ice hockey, it measures a player's goal differential. When an even-strength goal or shorthanded goal is scored, the plus-minus statistic is increased by one ("plus") for those players on the ice for the team scoring the goal; the plus-minus statistic is decreased by one ("minus") for those players on the ice for the team allowing the goal.Power play or penalty shot goals are excluded. An empty net does not matter for the calculation of plus-minus.
The statistic is sometimes called the plus−minus rating.
A player's plus−minus statistic is calculated for each game played, to provide a more meaningful measure over a full season. The statistic is directly affected by overall team performance, influenced by both the offensive and defensive performance of the team as a whole.
The NHL's Montreal Canadiens were the first team to track the plus−minus of its players, starting sometime in the 1950s. Other teams followed in the early 1960s, and the NHL started officially compiling the statistic for the 1967-68 season. While Emile Francis is often credited with devising the system, he only popularized and adapted the system in use by the Canadiens.
Only four players have been multiple single-season leaders for the plus−minus statistic: defenseman Bobby Orr led the league six times, Wayne Gretzky led the league four times, while John LeClair and Chris Pronger were two-time leaders.
Top 5: Season high
Top 5: Career high
Top 3: Season low
Top 3: Career low
Top 2: Single game high
Although the statistic was pioneered in the sport of hockey, it has found its way into use in other sports and areas of life. For instance, the NBA's Houston Rockets first utilized a modified version of the stat, which helped reveal the unheralded effectiveness of light-scoring Shane Battier. It is now in regular use throughout the NBA.