The Plus/Minus System evaluates defensive range and was created by BIS owner John Dewan in 2004.
The Plus/Minus system is simple: A player gets credit (a "plus" number) if he makes a play that at least one other player at his position missed during the season, and he loses credit (a "minus" number) if he misses a play that at least one player made. The size of the credit is directly related to how often players make the play. Each play is looked at individually, and a score is given for each play. Sum up all the plays for each player at his position and you get his total plus/minus for the season. A total plus/minus score near zero means the player is average. A score above zero is above average and a negative score is below average.
Plus/Minus is only one element of our Defensive Runs Saved system.