Wins above replacement
Wins above replacement, normally abbreviated to WAR, is an advanced baseball statistic developed to place a valuation on a player's total contributions to their team. Position players and pitchers have their WAR values calculated differently, but what they have in common is that a WAR value above zero represents a player making a positive contribution overall to their team, while negative values indicate an "average replacement" player would do better.
In general, a player's WAR will go up with more playing time, or with high success at batting, running, fielding and pitching, or both playing time and statistical success.
The statistic attempts to estimate the value of runs a player has contributed through their offensive performance (batting and baserunning), or runs denied to the opposing team through defensive actions like pitching and fielding.