Yes, this is another MVP Post, I apologize in advance. Skip to the break for the math portion, and a few conclusions.
First off- a mea culpa and some background: I'm a long time lurker, rarely a poster. So if someone else has already addressed this topic in detail, I apologize. In the analysis of this year's AL MVP the argument is set down sabremetrician vs traditionalist lines, or more simplified: WAR vs Triple Crown Stats.
Now don't get me wrong, I love WAR when debating best players, but not necessarily most valuable. It has always bugged me that WAR judges off a theoretical average replacement player, not the actual replacement players available in an organization. This makes it's perception of value somewhat distorted. If you're at all intrigued, follow me after the jump for a little math and hopefully some new light being shed on the AL MVP race.
Methodology: As previously stated, WAR judges all players off of the same baseline, which makes it a decent tool for raw comparisons of two players  . By utilizing Baseball References WAR stat, I intend to evaluate Mike Trout and Miguel Cabrera's Wins Above Team Eligible Replacement. This will be done by dividing total player WAR by their games played this season. then subtracting Miguel Cabrera's WAR/game from his available replacement, and the same for Mike Trout. Then re-multiplying out by their total games played this season.
The Replacements: Obviously, a few assumptions are made herein. The primary one being that both the Angels and the Tigers would be satisfied playing their theoretical replacements, and would make no moves to upgrade the positions over the course of the season. Also that no defensive alignment changes would be made, ie- Torii Hunter shifted to center in LA, or Jhonny Peralta making the move to third in Detroit, allowing for differential replacements. Finally, any prospects in either system will be treated as replacement level players, with a net impact of zero. Prospects are generally too hit and miss for me to want to take them into account.
I will utilize the MLB.com team depth charts to base my analysis, this means the WATER replacements are Danny Worth and Peter Bourjos. Though, the stat could be calculated using any other available replacements, ie- Don Kelly and Vernon Wells, if you so desired.
- Miguel Cabrera: 6.5 WAR over 158 games, WAR/game=0.04114
- Mike Trout: 10.5 WAR over 136 games, WAR/game=0.07721
- Danny Worth: -0.3 WAR over 41 games, WAR/game=-0.00732
- Peter Bourjos: 1.2 WAR over 98 games, WAR/game=0.01224
Miguel Cabrera WATER/game=0.04114+.00732=0.04846
Mike Trout WATER/game=0.07721-0.01224=0.06497
Miguel Cabrera WATER= 7.657
Mike Trout WATER= 8.836
Analysis: What was originally a 4 WAR gap shrinks to slightly over 1. That is still a statistically significant advantage for Trout. But not an overwhelming one. How much do you as an individual value a players contributions over the final month of the season? What is the value of a team making the playoffs?
Mike Trout is without a doubt the best player in the American league this season. However, accounting for the available replacements on each team, the fact that the Tigers will most likely reach the post season while the Angels watch from home, and the fact that Miguel Cabrera came through when his team needed it the most while Mike Trout "scuffled" (VERY relatively, frankly speaking) I firmly believe the Miguel Cabrera is the Most Valuable Player in the American League.