# How Is Plus Minus Calculated in the NBA?

The NBA’s plus minus statistic is a measure of a player’s impact on the game, showing how many points their team scores while they’re on the court.

## What is Plus Minus?

Plus minus is a statistic in basketball that measures a player’s impact on the game, represented by the difference in points scored while the player is on the court versus the points scored against the player’s team while the player is on the court. Plus minus can be applied to an entire team, or to individuals within a team.

## How is Plus Minus calculated in the NBA?

Plus minus is a statistic in basketball that attempts to measure a player’s impact on the game. It is calculated by subtracting the points scored by the player’s team from the points scored by the player’s opponents while the player is on the court. The resulting number is then divided by the number of minutes the player has played.

### Box Score Plus Minus

Box Score Plus Minus (BSPM) is a player statistic created by Justin Kubatko of Basketball-Reference.com. It is designed to measure a player’s contribution to their team’s scoring margin while they are on the court. Unlike traditional plus-minus statistics, BSPM accounts for all events that occur during a game, including fouls, turnovers, and free throws.

To calculate BSPM, Kubatko first creates a “box score” for each player that includes all of their relevant box score statistics (points, rebounds, assists, etc.). He then calculates how many points per possession each team scores and allows while each player is on the court. The difference between these two rates is the player’s BSPM. A positive BSPM indicates that the player is helping their team score more points than their opponents, while a negative BSPM indicates the opposite.

### On-Off Plus Minus

On-Off Plus Minus (OPM) is a statistic in basketball that attempts to measure a player’s impact on the game by comparing their team’s performance with and without them on the court.

The statistic is calculated by first finding the point differential for each team while a particular player is on the court. That number is then compared to the point differential for each team when that player is off the court. The difference between those two numbers is the player’s On-Off Plus Minus.

For example, if a player’s team outscores their opponents by 10 points when they are on the court, but are outscored by 5 points when they are off the court, then that player’s On-Off Plus Minus would be +5.

The On-Off Plus Minus stat can be applied to individual players or groups of players (lineups) and can be used to measure both offensive and defensive impact. It is generally considered to be more reliable than plus-minus statistics that credit or blame players for points scored or allowed while they are on the court, because it controls for factors such as team quality and opponent quality.

## What are the benefits of using Plus Minus?

Plus minus is a statistical measure used in basketball to evaluate a player’s impact on the game. It is calculated by subtracting the player’s points scored from the points scored by their opponents while they are on the court. Plus minus can be used to evaluate both individual players and entire teams.

While plus minus does not tell the whole story of a player or team’s performance, it can be a helpful tool in identifying strengths and weaknesses. For example, a player with a high plus minus may be playing well defensively but not contributing much offensively. Conversely, a player with a low plus minus may be scoring lots of points but also giving up lots of points.

Plus minus can also be useful for making in-game lineup decisions. For example, if a team is down by 10 points and their starting lineup has a negative plus minus, the coach may want to consider replacing some of those players with reserve players who have a positive plus minus.

In order to properly interpret plus minus statistics, it is important to consider other factors such as the quality of opponents and the playing time of individual players. A player who has played against poor competition and/or mostly during garbage time is likely to have artificially inflated or deflated plus minus numbers.

## What are the limitations of using Plus Minus?

Sports analysts have long debated the value of using plus minus as a metric to measure player performance. The reason for this debate is that plus minus can be affected by factors that are outside of a player’s control, such as the performance of their teammates. For this reason, some analysts believe that plus minus is not an accurate measure of individual player performance.