Whither Ryan Zimmerman?

Yes, we know, that it's only May, but it's time to start thinking about a sophomore slump for Ryan Zimmerman. His line has dropped 50 points. Last year, his line was .287/.351/.471. This year it has dropped to .250/.305/.417. Especially troubling is the 50 point drop in OBP; it suggests that rather than learning to be more patient, Zimmerman is taking the bait of pitchers who don't see much reason to throw to a dangerous hitter in the midst of a substandard lineup.Yes, it's only May, but Zimmerman has almost 200 at bats. That's more than enough to make this year so far a statistically significant sample.