What is going on here?

"Who the hell is Carlos Rosa?"

Good question. When scouring old posts from our archives, I randomly stumbled along this post. In it, NYRoyal said:

Since you poached devil_fingers from Royals Review, you really owe us a Carlos Rosa mechanics breakdown. It’s a moral imperative.

Interestingly enough (or not), I recalled that name from the article On That Stuff that I linked to a few days ago (which you read, of course) in the following paragraph:

Come to think of it, setting a minimum of 1,000 pitches for this analysis might have been a mistake. Given the precision and granularity of the data, this technique could be used to assess a pitcher's stuff given only a handful of pitchers. For example, I had never heard of Carlos Rosa before conducting this analysis, but now, from a sample of just 50 pitches, I can’t stop wondering why he’s not in the Majors. Great stuff. Decent control. The only evident knocks against him are his 2-8 Win-Loss record in AAA and 4.56 ERA. Maybe Dayton Moore knows something I don’t, or perhaps Rosa brought it just for his brief appearance in the Majors, or it’s possible GMDM is undervaluing a young talent who can get Major League hitters out. Actually, all three of these scenarios have probably taken place.

Given that the writer mentioned GMDM, it was pretty obvious that he at least knew of Royals Review, and thus, I had to finally write this piece despite the fact that NYRoyal requested it in December 2008. Since the Indians and the Royals are both pathetic this year, and the fact that I really do like the writers over at RR, I feel that this is the perfect time to deliver on the "moral imperative" that NYRoyal thrust upon me.

As such, I changed my MLB.tv login to something without a "+" in it (their older systems are apparently too stupid to understand Gmail sorting symbols) and pulled up Retrosheet to find when Carlos Rosa pitched last. It turns out that it was in June 2008, which is quite a bit farther back than I had anticipated. Fortunately, MLB.tv ended up working out alright, and here's what I found...

Tempo: Rosa is at 18-19 frames from maximal leg lift to footplant. Very Good.

Arm Action: Rosa gets his arm up early using a pretty solid arm swing that goes down, back, and up. He doesn't excessively reverse rotate his shoulders towards home plate. I'm liking this guy more and more... Very Good.

Ball Release: Rosa tilts his trunk to get a downwards plane release on his pitches and does a good job of pointing the gloveside shoulder into the target. I can't tell if he pronates the releases of his pitches, but it looks like he throws a slider, so I doubt it. Still, not bad! Above Average.

Followthrough: I don't particularly like his followthrough phase, as he lets the glove arm hang down and it causes incomplete shoulder rotation through release, but it's definitely not terrible. I'd grade it as Below Average.

So I figured Carlos Rosa must not be having a great year in Omaha or something, but it actually turns out that he's doing rather well! Sure, his ERA leaves something to be desired, but a 10.1 k/9 isn't exactly something you find on trees.

Why is this guy not in the majors for a team that is going nowhere?