Based on Fangraphs data, for those starters who qualified in both 2007 and 2008:
– Biggest increase in FB%: Livan Hernandez, +12.40% (if he’s gonna get paid to pitch to contact and be crappy, why waste time with those curveballs and changeups?)
– Biggest decrease in FB%: Jeff Suppan, -9.40% (if you had Jeff Suppan’s fastball, you’d throw a lot more sliders too.)
– Biggest increase in SL%: Derek Lowe, +12.60% (wily vet, keeping it fresh?)
– Biggest decrease in SL%: John Maine, -11.50% (who knows)
– Biggest increase in CB%: Cole Hamels, +3.30% (boring)
– Biggest decrease in CB%: Bronson Arroyo, -9.90% (This is probably a classification issue — THT notes that his curve/slider are very similar, and lo and behold, he throws 9.6% “more” sliders this year.)
– Biggest increase in CH%: Scott Olsen, +8.70% (to augment his problematic fastball)
– Biggest decrease in CH%: Jamie Moyer, -7.90% (who knows. See Derek Lowe?)
I think looking at changes in slider/curveball numbers from year to year would be, in some instances, an interesting way to explore how pitches are classified, and whether or not these guys actually are going back and forth between slider and curve or whether the algorithms are classifying them differently.
Kaz isn’t holding off on the slider to save his arm– he just hasn’t had it since his mechanics have been messed up. The man definitely needs that slider. Sure, his results look fine, but there’s nowhere near the degree of confidence that fans could have in him in ’06 and the second half of ’07. He looks like first half ’07 Kazmir, who batters fouled off over and over again until he left the game after 5 innings. He really needs to figure his slider out.
I’ve also been noticing this. Actually a Rays site also brought this up earlier this month, but it’s good to see other people are noticing the same thing. He has been throwing it a little bit more latey.
I have to say, I’m always deeply skeptical when people start to look at pitches to explain pitching. There must be some relation, but I don’t know that anyone knows what it is. As far as I’ve seen, looking at pitches to explain pitching remains a speculative art rather than science at this point–I’m really hoping the Pitch F/X helps us rectify the situation.
Since Kaz saw a 10% drop in his slider rate from 2006 to 2007 with no corresponding drop in his GB% (42% to 43%), I don’t think that the evidence that your presenting really supports your case. If the slider is the explaination, we should expect to see a linear decrease in GB% with the linear decrease in slider tossing. But that’s not what we see.
Comment by philosofool — August 24, 2008 @ 11:12 pm
I should explain just a little of that last comment: when I talk about using pitches to explain pitching, I’m talking about the relationship between individual pitches and the outcomes of plate appearances and balls in play. I don’t think anyone yet understands what the relationship between individual pitches and individual plate appearances is.
Comment by philosofool — August 24, 2008 @ 11:22 pm