Inspired by commenter Russ, who in the Thursday morning game recap thread asked whether CC was giving up more fly balls of late than he’d been, I turned up the following data.
Beginning of the season through August 5:
From August 6 on its:
I also found that over his last four starts he’s been throwing quite a few more sliders than he had been.
That roughly 8% uptick in sliders has corresponded with a 5% drop in the changeup and 3% decline in sinker use. CC’s location for each of his four main weapons is nearly identical in both data sets, so it hasn’t been a control issue. He’s coaxed slightly fewer swings out of the slider but maintained his whiff rate and has also seen significantly fewer sliders fouled off. So far nothing in the slider data really jumps out.
The other notable changes are the fact that the sinker saw a 10% increase in being put in play, while the changeup jumped from a 16.3% whiff rate to 26.3%, which is crazy. The change also saw a significant decline in Foul% and was even put in play slightly less. With such a high rate of success on the change, I’m not sure why Sabathia’s eschewed some of its use in favor of the slider. Without looking, I’d imagine he’s probably faced a higher percentage of lefthanded batters over his last four starts than usual.
I was also curious to drill down a bit further on the batted ball data:
Here’s where the increased slider usage has gotten CC into some trouble. Righties had been pounding the slider into the ground 55.2% of the time, but have hit zero grounders over his last four starts, while hitting it for line drives 25% of the time and putting it in the air a whopping 75% of the time. Even lefties are hitting it for a line drive 27.3% of the time.
Then again, righties have also been hitting fewer groundballs on the change while ripping it for a line drive 44% of the time, so that may also partly explain Sabathia’s decrease in changeup deployment.
One other interesting note on the slider — it turns out Sabathia’s slider is frequently mistaken for a curveball (I for one thought he threw a semi-regular curve, but per the pitchfx data he’s thrown one less than 1% of the time this season), and I’d imagine that’s due in part to the fact that he throws it slower (~82mph) than the MLB average slider (which is around 84mph).
CC also seems to have had more trouble than usual with his bread-and-butter. Of the seven home runs he’s given up over the last four starts, five have come on four-seamers, and all five of those four-seamers were to lefties — a grouping of hitters he typically owns. This could just be a coincidence, but it doesn’t seem out of the realm of possibility that CC may have gotten somewhat gunshy with the fastball, leading to an apparently slightly more hittable and frequently used slider.
In any event, all of this is likely much ado about nothing given that we’re talking about a pitcher the caliber of CC Sabathia — not to mention a tiny four-start sample size — but nevertheless hopefully this sheds some light on why the results of late haven’t lived up to the superhuman bar CC has set.