What's The Deal With CC's Fastball?

(If "this" is the 4-seamer, then yes, people can definitely touch "this.")

There are 4 things that have defined CC Sabathia's 2012 season so far: eating innings, limiting damage, rough starts to games, and consistently poor fastball command.  The first 2 things are nice, and something that anybody would want in a starting pitcher, but the last 2 are the bigger issues.  They are undeniably linked together and the easiest things to point to when explaining CC's less-than-ace-like 3.80/3.41/.3.29 slash line.  The high HR rate is also a contributing factor, but even that can probably be tied back to the lack of fastball command and the resulting poor location in the strike zone.  This has been a hot topic of discussion over on the AB4AR Facebook Page (hint, hint- "Like" that shit), and everybody has reasonable theories for what the cause is.  So what's the deal here?

Fastball command has been a constant trouble spot for CC since Spring Training and, save for his lights out 24-inning run from late April to early May, has remained at the forefront of any post-CC outing discussion since.  Looking at the numbers, it's clear as day that this isn't just guys getting lucky and running into more heaters than they should be.  PITCHf/x has CC's velocity on both his 4-seamer (92.3 MPH) and sinker (91.7) way down this year compared to the low-to-mid 93 MPH range that they sat in last season.  CC has always been the type to really start heating up when the weather heats up, but it's mid-June now and he hasn't shown any signs of additional oomph on those pitches in his 3 starts this month.

The decreased velocity and inability to locate those pitches down in the zone and on the corners has them sitting at below-average values right now (-3.8 for the 4-seamer, -9.6 for the sinker), something that is almost unthinkable for CC given what he's done since putting on the pinstripes.  The trend for the 4-seamer shows that its effectiveness has been declining since 2009, but it's still almost inconceivable to imagine CC having a below-average fastball.  To counter for this weakness, CC has been throwing fewer 4-seamers this year (40.9%) and leaning heavily on his slider, which has easily been his best pitch.  But with word getting around that his fastball isn't as dangerous as it used to be, hitters can be less worried about that slider and more keyed into the fastball in certain counts.  The lack of a quality fastball is likely also negatively affecting CC's ability to mix in changeups and keep lineups more off balance the 2nd and 3rd time through.

As for what is causing these ongoing fastball problems, I'm not really sure.  The simplest explanation would be to say that CC is hurt, but his strikeout (8.97 K/9) and swinging strike (11.7%) numbers don't support that.  If CC was pitching hurt, we would be seeing decreased effectiveness on all his offerings.  Instead, we're seeing the highest K and swing-and-miss numbers that we've ever seen from CC during his time as a Yankee.  The more likely explanation is that there is something mechanically wrong with him right now.  Maybe it's arm angle, maybe it's grip, maybe it's release point, but it has to be something.  That's the only way I can see the continued fastball problems and continued high strikeout rates making sense.

I'm not a doctor, and I'm not a pitching coach.  None of us are.  But it doesn't take either of them to notice that something is amiss with CC and his heater right now.  Every pitcher likes to work off the fastball, and every pitcher is more effective when he can do so, but for CC it's even more important because command of his fastball is what allows him to get ahead in the count, and it opens up the multitude of offspeed options for him to choose as out pitches.  The one good thing about all of this is that the rest of the rotation's recent dominance has prevented this from becoming a glaring issue, but to get their ace back to being ace-y, the Yankees need CC to fix whatever is wrong with the old Number 1.

(For more on this mystery, check out Mike Axisa's post from earlier today on RAB.  He has his own theory for what the root cause of this problem might be, and it makes sense.)