Much has been made about Trevor Cahill's struggles this year. Let's not kid ourselves, he's having a pretty tough year. Although not as tough as Craig Breslow, Cahill has shown a major kink in his Lego armor. And with injuries making the starting rotation as bare as the downtown of Gary, Ind. these struggles have only been magnified. Sure the once exception to the sabermetric rule, which is now being held by Moscoso (I swear it's Black Venezuelan Magic), was going to regress as some point it time. But this much? I don't think Trevor's problems are the numbers. I would wager that he will, at some point in time, get close to where he was. I think the answer is as simple as his mechanics.
Now I am going to take this moment to make a disclaimer: I am not Curt Young or Dave Duncan, and I hopefully don't try to make myself sound like one. I have been lucky enough to play highly competitive baseball at every amateur level and having coached this aspect of the game for the last 3-4 years, I think I have a slightly better working knowledge of pitching than the average fan. Now, onto the rest of the post.
Baseball is simple. Even more so than the basic breakdown of "see ball, hit ball, throw ball." Baseball is simply straight lines and angles. A geometric dream and a right-brain nightmare. When it comes to pitching the idea of straight lines is paramount.
At the high school that I used to coach at we broke pitching into six component parts:
1- Start (wind-up or stretch)
2- Drop Step
5- Tuck Turn
6- Extend and Finish
All of those should be pretty self-explanatory for those who watch/or have watched any baseball. The one I want to focus on with Trevor Cahill is the milisecond between numbers 4 and 5.
The power position is the point of the delivery where the pitchers front foot has landed and they are in the preffered posistion of making the 'goal posts' or the 'L' (read: not the way Tyler Clippard is). The 'Tuck Turn' comes moments after when the pitcher will bring his glove to his chest, or vice-versa, and exlpode with the hips (much like hitting the baseball). And it is here where I feel Trevor is having problems.
The problem that you will find between numbers 4 and 5 is, for some reason, the front side blows out and and the arm drags through the zone. After that one of two things will happen; 1)if the pitcher is holding on the the ball to hard and will pull it to opposite side of the plate (for Trevor outside on a righty) or 2) the arm drags and the ball is left arm side. Either way, it leads to wildness.
Trevor, much like Chen-Ming Wang, is a sinker ball pithcer. Part of being the sabermetric darling was the fact that he kept the ball low and induced weak contact. But when you start leaving that sinker up, you get hit hard. You saw this with Chen-Ming Wang post groin injury. He would 'jump' off the rubber trying to not only get on top of the ball but to also get pressure off his leg. Subsequently he got drilled.
Have a gander at these two strike-zone plots of Trevor from BrooksBaseball.net:
The first graph was his start last night and the second one was his start against the White Sox when he lasted only two inning. A bit of cherry-picking, I know, but they illustarte my point perfectly. Looking at the graphs you notice how last night his pitches clustered lower in the zone and on the corners, whereas against the CWS they clustered up in the zone where where it is much, much easier to hit a sinker, let alone any pitch.
And that's where the straight lines in pitching come into play. If Trevor squares the front shoulder to the plate and stays through the pitch, he's untouchable. It's when he tries to make the perfect pitch or simply does not repeat his delivery, he gets shelled. There is hope for having old Trevor back. Hopefully he can work on this with what is left of the season and during the off-season.
Again, I am not a pitching guru....yet. Simply diagnosing what I see.