Plus−minus (+/−, plus/minus) is a sports statistic used to measure a player's impact on the difference between their team's total scoring versus their opponent's. In ice hockey, it measures a player's goal differential. With the exclusion of power play and penalty shot goals, when an even-strength 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. Whether or not the net is empty does not matter for purposes of plus–minus.
While the statistic officially measures a difference, it is sometimes (inaccurately) referred to as the plus−minus ratio or plus−minus rating.
While a player's plus−minus statistic is calculated for each game played, it tends 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 plus−minus is mainly used to examine the performance of defenders and forwards who play a defensive role, while offensive forwards are more often measured by their scoring statistics (goals and assists). Defensemen tend to lead the plus−minus statistic more often than forwards, since they log more even-strength ice time – though high-scoring forward Wayne Gretzky was the season leader in the National Hockey League (NHL) in four different years.
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.
Notable players (NHL) 
Only four players have been multiple single-season leaders for the plus−minus statistic: defenceman 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
- Bobby Orr, 1970–71, +124
- Larry Robinson, 1976–77, +120
- Wayne Gretzky, 1984–85, +98
- Dallas Smith 1970–71, +94
- Guy Lafleur, 1976–77, +89
Top 5: Career high
- Larry Robinson, career, +730
- Bobby Orr, career, +597
- Ray Bourque, career, +528
- Wayne Gretzky, career, +518
- Bobby Clarke, career, +506
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.
Other uses 
- Fitzpatrick, Jamie. "What is the "plus–minus" statistic and how is it calculated?". About.Com.
- The Plus and Minus of Plus-Minus - LCS Hockey
- Lewis, Michael (2009-02-13). "The No-Stats All-Star". The New York Times.
- Jim Chen, Plus/minus and the problem of measuring Arschlochkeit, Moneylaw, July 22, 2008