Happy Biogenesis Day everyone. There's going to be plenty of Alex Rodriguez coverage and PED talk today, so I decided to go another route for those that might get bored with the suspension news. I've reiterated a number of times that I have faith in CC Sabathia going forward. Numerous articles I've written have talked about his velocity, his mechanics, his changing of deliveries, but even with velocity spikes and bullpen sessions, Sabathia is still struggling to avoid hard contact.
By no means do I think I can solve Sabathia's problem, but I have my own theory on why this slump occurred. During this 2012-2013 offseason, the starter both lost weight and had elbow surgery. When he returned, he showed a significant loss of velocity, but by May that had all returned. I think that there's a chance that the combination of weight loss and time off during the surgery caused muscle loss and thus velocity decline. Though the lefty is now sitting at the same velocity he owned in 2012, he may be overthrowing to get there, and thus the mechanics have not been as efficient.
Sabathia continues to display that he throws hard and with control of the strike zone, but he has not shown the same command. Unlike the past four years, Sabathia's pitches are not hitting their targets. Overthrowing can often leads to mechanical troubles, and in Sabathia's case, his timing seems to have deteriorated the most.
The GIF above shows Sabathia pitching from the windup on Friday night. Two fastballs called for in the same location are displayed above, one misses it's target in the dirt, while the other is perfect and results in a groundball. (A hit in this case, but regardless it was the result he wanted.)
It's hard to see much of a difference in his mechanics in the first GIF, but the second one above focuses on the release point on foot strike. Both clips are timed at the release point of his pitch, and the results show the follow-through of his left arm is one frame faster than the other. In this case, Sabathia has over rotated his shoulders, causing the pitch to end up down and away from his target. Though the example isn't pictured above, examples of under-rotation of his shoulders were also prevalent in Friday's game, where the pitches would end up in and in from his target.
But over and under rotation of the shoulder are normal struggles for pitchers. It seems to me that Sabathia has dealt with this much more often in 2013, and it's a clear deterioration of his timing. Since his mechanics have hardly changed since 2012, this should support the theory that he's overthrowing.
Doug Thorburn of Baseball Prospectus did a similar analysis last week on Sabathia. He found that many of the hard hit balls delivered by Sabathia were in fact on balls left up in the zone, in this case under-rotation of the shoulder or what he called "not reaching full extension at release point."
In his start on Friday, it seemed that Sabathia was well aware of his previous under-rotation, and may have compensated with over-rotation. For the most part, this is much less likely to lead to big hits, since the location of the pitches will end up lower than the target rather than up in the zone. While it's less likely to be hurt when you're over-rotating, Sabathia had trouble finding the strike zone in the first inning, with most of his missed targets falling down and away from Stewart's glove.
Thorburn also adds that the combination of velocity loss and command issues have ultimately made the lefty less likely to get away with mistakes, but I would disagree with this conclusion. Sabathia's velocity has largely returned on average, and he's proven that a 92 - 93 mph fastball can work over the last few years. Instead, I believe reduced velocity has been the main factor in his command issues, and that overexertion to get to his old velocity has worsened his timing. I don't believe Sabathia is as strong as he was last season, and that's why we're rarely seeing his max velocity anywhere over 95 mph.
By no means do I want a fatter Sabathia, but with any sort of weight loss, there will be both fat and muscle degradation. Assuming he didn't weight train due to his recovery from elbow surgery, loss of muscle obviously means less strength. It explains the drop off in velocity in April, and perhaps the lack of a high max velocity at this point.