Interesting "rumor" on SI's Truth/Rumor section. Apparently a study shows that umpires in baseball call a pitch a strike about 1% more often when the pitcher is of the same race as they are, which may or may not be a product of implicit association/latent racism.
Overall 1% is statistically significant w/ the sample size they've taken, but even then it's not much: about 1 pitch per game. Now admittedly there are situations where 1 pitch can change an an at-bat, an inning, and even a game: say, bases loaded, 3-2 count. But probably this just means that a hitter flies out on a 2-2 count instead of a 1-2 count a lot of the time.
Anyways, just some food for thought. Still doesn't explain why Dontrelle Willis sucks so badly this year.