MVP Watch, Part 1: AL

Recently I did a lot of work with Win Probability Added (WPA). I developed a system to adjust WPA for position (as a 1.5 WPA from a C is more valuable than the same WPA from a 1B).

Then, a couple days ago, at The Hardball Times, I discovered that Ultimate Zone Rating (UZR) had been posted for the first two months of the year.

I thought it would be an interesting excercise to combine these two statistics and see which American League players have been most valuable to their teams over the first two months of the season. I'll do the NL tomorrow.

First, I took the top 20 AL hitters in WPA from FanGraphs.

Taking these, I then adjusted them based on position. Note that I have changed my adjustments so they are now based on PA, rather than AB. Here is how much each of these players' WPAs changed with this adjustment.

In short, adjusted WPA adjusts a player's WPA based on what an average player at his position would have done in the same number of plate appearances. A more detailed explanation can be found here.

Adding this number to each player's WPA gives us Adjusted WPA. But that is only half the story- fielding must also be taken into consideration.

UZR is given in runs. When adding it to Adjusted WPA, I divided it by 10, since, generally 10 runs is equal to one win.

Vlad has been so much better than everyone else in terms of regular WPA, it would be almost impossible for anyone to make up for it with the positional adjustment and UZR.

Grady Sizemore does makes a valiant effort, as he is first in UZR (+12) to this point in the season. This allows him to move from seventh in WPA to second in value.

The player most adversely effected? Wouldn't have been my first guess- Derek Jeter. The controversy about Jeter's fielding value has been well documented. Since he indisputably plays SS (not even Neyer could argue that point), his bat has some extra value in the posititional adjustment.

Then comes UZR. There are 584 players listed in Lichtman's ratings. Derek Jeter comes in 574th, at -7 runs.

To me, this combination of adjusting WPA and incorporating fielding stats is very interesting. Casey Kotchman, the Angels' first baseman, loses .47 becasue of his position, but gains almost all of it back with his UZR of 4.

I always thought this was one of the most difficult parts when comparing different positions. Not only do you have to compare each player's bat's value based on their position, but how valuable they are defensively at that position.

This is very difficult to do, but I feel this system does that pretty effectively.

If you have any questions, comments, or suggestions, please e-mail me at jnwheat@emory.edu, or post something in the comments section below.

Back with the NL tomorrow.