Here are his PA/BB ratios by season for his career:
2006: 325 PA, 51 BB (6.37 plate appearances per walk)
2007: 263 PA, 33 BB (7.97)
2008: 274 PA, 35 BB (7.83)
2009: 432 PA, 40 BB (10.80)
2010 (as of August 5th): 352 PA, 24 BB (14.67)
As you can see, over the course of his career, his plate appearances per walk ratio has more than doubled which means his walk rate has essentially been cut in half. And it's been more or less a steady decline with only a slight increase in walk rate from 2007 to 2008.
In 2006, he hit a career low .228 but posted a .360 OBP which is only second to his .374 OBP in 2008 in which he hit a career high .273. That is a .045 point jump in BA but only a .014 jump in OBP. This year his slash line is .254/.324/.486. Juan Rivera would be proud.
So my question is...WHAT HAPPENED TO HIS PATIENCE?
Has he become more aggressive due to increased confidence in his hitting ability? Or has he just been plain Mickey Hatcherized?
Feel free to jump in with your theories and explanations.