Like any other stat, it's not definitive and you can't use only one year.here's certain things you have to understand about WAR. I'll let Jonah Keri explain it:
FanGraphs ranks every major league player using a measure called Wins Above Replacement. WAR combines a player's offensive and defensive value, adjusts for park effects, the position he plays and other factors, then weighs that player's value against your typical 25th man or waiver-wire refugee. A one-win player is a good relief pitcher, half-decent fifth starter ora low-end starting position player. A four-win player is All Star-caliber. Anything above that and you're elite.
Mauer was worth 8.2 Wins Above Replacement for the Twins, an astonishing number that's up there with Albert Pujols' best efforts. Yet Mauer ranked just 2nd in the AL, trailing Zobrist and his off-the-charts 8.5 WAR. Zobrist's season was so astonishing that he actually finished a tick above Pujols (8.51 vs. 8.46 WAR). That's right: Ben Freaking Zobrist, by one measure, is the best position player in the world this season.
Let's get some caveats out of the way first. FanGraphs ranks Zobrist's defense alone as more than two-and-a-half wins better than a fringe player. The stat used to measure that number is Ultimate Zone Rating, a solid defensive measuring tool that's up there with anything we have today. But just as you would want three years of ballpark data before compiling park effects numbers, so too does UZR work best when looked at over a three-year stretch. Meanwhile, Mauer gets dinged because catchers' defense is not counted in UZR. Zobrist is a very good defender at second base and right field. We probably shouldn't expect him to be a mix of Frank White and Roberto Clemente for the next 10 years, though.
So yes, Zobrist did beat Mauer and Pujols, but that's because catcher's D isn't included in UZR and Zobrist's D was overvalued. Notice that Pujols blew away the competition in the hitting portion of WAR (
http://www.fangraphs.com/leaders.aspx?p ... 09&month=0). Still, everyone at Fangraphs (unlike some media members) agrees that Mauer and Pujols are the runaway MVP winners . Zobrist is no chump, though. He definitely deserves the most 2nd place MVP votes, which I'm sure will go to Derek Jeter.