In 2009 Matt Capps had a BB/9 of 2.82 which is over a walk an inning higher than his career average. It was also over two walks an inning higher than his 2008 mark. Stranger still Capps had almost identical Strike to Balls (S/B) ratios in those seasons: 2.08 in 2008 and 2.07 in 2009. How we can explain this apparent discrepancy?
A higher percentage of batters saw two or more balls from Capps in 2009 versus 2008. In 2008 batters saw two or more balls 30.5% of the time while in 2009 that number was 35.8%. Batters saw three or more balls 11.4% of the time in 2008 while in 2009 that number was 14.3%. Hitters ended their PAs in 3-0, 3-1, and 2-0 counts nearly twice as often in 2009. Capps also ended PAs in 0-1, 0-2, and 1-2 counts 5.4% more of the time in 2009 and batters found themselves in two strike counts 7.7% more frequently in 2009.
What these numbers suggest to me is that although Capps's control had not diminished in 2009 versus 2008 - he was capable of throwing about two strikes for every ball in both years - but the pattern in which he threw his pitches had changed. Capps "bunched" his pitches in 2009, meaning when he threw strikes they tended to come in bunches, and there was a similar trend in the balls he threw. This describes the pattern we see in the data: hitters saw counts with many balls and few strikes and vice versa at higher rates in 2009 versus 2008, but the constant S/B ratio in 2008 and 2009 ensures that they did not see even counts as frequently in those years.
My thought is that Capps' bunching came as a result of his pitch selection. In 2008 14.8% of Capps' pitches were sliders versus 25.0% in 2009. It is possible that Capps tended to go with the slider when he fell behind batters, leading to more balls. Conversely when Capps got in front of batters he may have found it easier to stick with the fastball and to get hitters to chase the slider, both leading to more strikes.
To fix this problem Capps could go back to his 2008 pitch selection. I think this could lead to a significant decrease in his BB/9. Unfortunately for Capps, however, his fastball and slider saw decreases in effectiveness in 2009. If he were to switch back to throwing fastballs 78.6% of the time - as he did in 2008 - and his fastball were the same as last year, Capps would probably get hit even harder than he did in 2009 (which is a little tough to believe considering he had a .370 BABIP, .324 BAA, .533 SLG, 1.66 HR/9 that year).
It seems that no matter how you look at it Capps is in trouble for 2010. Switching back to his 2008 pitch selection would probably cause Capps to walk fewer batters but also increase his chances of getting hit hard. Staying the course would probably result in a season on par with 2009. Of course this all assumes that Capps' fastball and slider will be at the same level in 2010. If, as Capps claims, coming into camp in bad shape (as mentioned in an earlier post of ours on Capps) increases his abilities, then maybe a hefty season can make all of my predictions look silly.