Winning Percentage (WPCT) | Glossary | MLB.com

DefinitionA pitcher's winning percentage is calculated by dividing his total number of wins by his total number of decisions (wins plus losses). Pitchers who get the win or the loss are known as the "pitchers of record" in a game, and winning percentage indicates how frequently a pitcher wins when he is the pitcher of record.In A Call"win-loss percentage," "win-loss record" (which describes the two-number statistic that encompasses the pieces of winning percentage; for instance, if a pitcher is 3-2, his winning percentage is .600)