WAR. What is it good for? Absolutely something if you think Angels rookie Mike Trout should win the American League most valuable player award over Detroit slugger Miguel Cabrera based solely on this advanced metric, which stands for Wins Above Replacement. But what is WAR, exactly? It attempts to quantify a player's overall contribution — hitting, baserunning and defense, for position players — and is expressed as the number of wins a player adds to his team by comparing his performance with that of a fictitious "replacement player," assumed to be an average triple-A call-up. A WAR of 3.0 is good. A 5.0 would be All-Star caliber. Trout entered the weekend with a major league-leading 10.5 WAR, according to Baseball-Reference.com's formula. (There are other formulas used by other statisticians.) That's more than three wins better than Robinson Cano, who ranks second in the AL with a 6.9 WAR, and Cabrera, who is third with a 6.6.