Mat Latos and the missing slider

Fangraphs posted an article yesterday discussing Mat Latos' early season struggles, which served as an effective reverse-jinx setting up last night's win against San Francisco. The major takeaway is that Latos has relied much less on his slider during his brief career as a Red:

Latos has altered his repertoire since coming over to Cincinnati. In his brief career, he has typically used his slider about 27% of the time. It has historically been his best pitch at just over a run above average per 100 pitches in both 2010 and 2011 and generating a whiff rate at about 24%. But he's dropped his usage of the slider by about 10% in 2012, with increased reliance on his change.

Last night may have been Latos' best Reds start to date, but in throwing his slider just 17% of the time he continued the trend of decreased usage of his best breaking ball. That trend is particularly strange because Latos used his slider more as last season wore on, which, along with increased fastball velocity, made Latos much more effective in the second half of last year. ESPN notes that Latos' slider ranked second-best by whiff rate among the 90 starting pitchers that threw at least 300 sliders. So why is he shying away from it in 2012?

The theory posited in the Fangraphs article is that the Reds have altered Latos' delivery point to prevent injury. The Pitch F/X charts show that Latos now throws from a less over-the-top arm angle. Fangraphs believes that this has helped his fastball gain additional horizontal movement, but it's also made his slider much straighter than before. I'm not sure that I buy the arm-angle story, however. To my eye, the release point charts in 2011 and 2012 don't look noticeably different. The top chart is all sliders thrown in 2011, and the bottom is the same for 2012:

via pitchfx.texasleaguers.com

Again, I'm not seeing a difference but a more discerning eye may be able to correct me. In looking at the numbers, Latos' 2012 slider is consistent with last year's version by velocity and horizontal movement. But not by vertical movement. In 2011, Latos' slider dropped almost 2" more than a normal pitch. That allowed him to bury his slider just below the bottom of the zone, luring hitters to swing away at what appeared to be hittable pitches. This year, however, the drop has been just about a quarter of an inch.

Last night, I expected to see Latos try to work in the slider as a two-strike pitch more often, particularly against righties. During Latos' somewhat labored sixth inning, Buster Posey came up with two outs and men on first and second. Latos threw a first pitch slider in the dirt. After getting two strikes, Latos went with a changeup before going with a fastball or cutter for five straight pitches. Finally, on the ninth pitch Latos threw his second slider to Posey, and again it was in the dirt. Latos and Hanigan did not have much confidence in calling the slider, perhaps justifiably so given the two in the dirt that bookended the PA.

About that sixth inning, Latos said "You just have to regain focus and go back after it and say, 'Here's the No. 1, hit it.'" While it was great to see that Latos wasn't afraid to use his mid-90s heater to put away batters, here's hoping that he can regain command of his devestating slider. It's not gonna be easy to strike out a batter an inning without it.