A couple of weeks ago, I wrote about CC Sabathia's 2014 adjustment on the mound, which included a more sinker-heavy repertoire and a move to the far right side of the rubber. Both of these adjustments indicate that CC Sabathia is looking for ground balls and strikeouts, as it's generally believed that the break on a sinker plays better from the third base side of the mound for an aging left-handed pitcher. So far, Sabathia's peripheral stats look great, but the results have been mixed. He owns a 48.3% ground ball rate, with his sinker generating 12% ground balls this season, a 9.39 K/9 and a 1.96 BB/9. These are great peripherals reminiscent of the old Sabathia, however his HR/FB rate is now at 23.3%, meaning nearly one out of every four fly balls are home runs.
While Sabathia moved to the third base side to play up the movement on his sinker, it looks like the new approach has massively hurt his four-seam fastball. While he's throwing the four-seamer and sinker in nearly equal distribution, four of his 10 home runs have been off the four-seamer, two came off the cutter, and one from the sinker. In fact, all six of these home runs off the straighter four-seamers and cutters have been off right-handed hitters. It seems that moving into the third base side has helped right-handers see his straight fastballs.
If Sabathia is going to continue throwing from this side of the rubber, he'll need to drastically cut down on his four-seamers to right-handed hitters. His sinker has been fairly effective against them, especially when you consider the bad luck he's had with ground ball so far this season. Sabathia's four-seamer against righties has just been terrible, there's no bad luck here, and there's no reason to continue to throw the pitch when he has a successful history of using the sinker, changeup, and slider against them. His new cutter has also been terrible, and according to Harry Pavlidis' pitch ID's at Brooks Baseball, he hasn't earned a single out with it yet.
The four-seamer is still a weapon against left-handed hitters, and it's something he may be able to work in slowly as his velocity increases a little by mid-summer. At the moment, the pitch is killing him against right-handed hitters, and at the moment it looks like the major root of his trouble. Though his new approach is putting up some gaudy strikeouts, walks, and ground balls, if Sabathia continues to throw the four-seamer and cutter to righties as he is now, there looks to be no end to his home run problem.