On Thursday, using PITCHf/x numbers, I wrote about CC Sabathia's recent troubles. It looks like his velocity had returned in his start on 5/26, where halfway through the game, Sabathia was sitting between 92 and 93 mph. With the velocity issues solved, but his struggles continuing, I pulled all of his pitches from 2013, and sorted them by pitches put in play and swinging strikes. In the end, the movement on his four-seam fastball had the biggest impact on the results. Sabathia was systematically more successful when his movement decreased, but unfortunately for the southpaw, he was throwing with a ton of vertical and horizontal movement this season. I hypothesized that he may have been too healthy, and that his clean elbow and/or weight loss could be adding spin to his four-seam, and the additional movement was affecting his control and fly ball rates. After a disaster of a start on 5/26, Sabathia came back to throw an incredible game against the Red Sox. I was interested to see what kinda of movement he was sporting in this start compared to his previous, and I was a little surprised to see the significant difference between these back-to-back performances.
At first I thought that the PITCHf/x cameras in Tropicana Field or Yankee Stadium on 5/26 or 5/31 were mis-calibrated, but the opposing starter in each game, Alex Cobb and Jon Lester, showed the same movement they had all season. All of Sabathia's pitches from 5/31 had the same vertical movement as his previous start, but outside of the changeup, the horizontal movement on all of his pitches decreased by three inches. The average horizontal movement on his four-seam reached 7.1 inches into left-handed hitters on 5/26, but on 5/31, he averaged 4.49 inches. This 3 inch decline remained true for his sinker and slider as well. I expected some sort of change in his release point, perhaps lower in this case, but it remained exactly the same according to PITCHf/x.
There are no noticeable differences in mechanics here, his timing is identical, and the release point again looks similar. What we know for sure is that he's spinning the ball less, so perhaps it's in his grip.
But according to Chad Jennings of LoHud, Sabathia said he made no significant changes in his mechanics during his bullpen. He attributed the success to being sharper and more aggressive.
“When I was younger, I did (care about velocity),” he said. “I thought that was the way I was getting guys out. As I got older, I know it’s more location than it is velocity. … I didn’t feel that much different than I did (giving up seven runs) in Tampa, but just being aggressive in the strike zone and attacking guys, that was the biggest difference.”
Despite attributing his success to simply sharper stuff, I would like to believe there is something that would significantly decrease the horizontal movement on his pitches. But to be honest, I don't see anything yet, and all I'm left considering is the hot weather that night. Perhaps the heat slowed him down a bit.