[clydepepper]

Originally Posted by nat

WAR would be completely unrelated to wins if its components didn't correlate with wins, but they do. You can take its components and run a regression analysis to see how closely they correlate (and the people who developed WAR did just this).

The positional adjustment is in there because some positions are harder to play than others. Trout may be a poor CF, but center fielders need to cover more ground than do right fielders. If he was a right fielder he'd catch a higher percentage of the balls that are his responsibility than he does now. (Likewise Betts would catch a lower percentage of balls if he played CF.)

Defensive stats are subject to enough noise, though, that you should really use a range of years of performance when evaluating a player, and you should certainly be doing that this early in the season. So far this season Trout has a 5-run advantage over Betts on defense (that includes the positional adjustment). That's not much, and it will probably be gone by the end of the year. Trout is a roughly average CF and Betts is a really good RF, by the end of the season Betts will almost certainly catch enough extra balls to he'll come out ahead in the defensive component of WAR. (In fact, WAR says that for his career Betts has save far more runs than Trout has, even though Trout has been in the league longer.)

There's another one.