Preston Claiborne has now thrown 97 pitches out of the Yankees bullpen this year since being promoted from AAA, what you might conservatively call a start.
First, lets look at his stuff:
63 Fastballs: 94.14 MPH, Jason Frasor
19 Sliders: 84.96 MPH, Derrick Turnbow
15 Changeups: 87.67 MPH, Kyle Farnsworth
Picked out of the 17th round out of Tulane by the Yankees in 2010, Claiborne has never been a rated prospect. He has purely been a bullpen pitcher in his professional career, so that is one reason why, but the fastball is clearly a MLB fastball. To go a little further on the Frasor comparison, Frasor doesn't throw a changeup, and his slider isn't as hard as Claiborne's.
Claiborne's average release point so far is 6.14 vertically, and -.86 horizontally. His closest comparison is probably Greg Holland, who has a dominating 58 FIP - in his career with somewhat reverse splits.
While the sample size is obviously small, we can get some idea of how Claiborne is trying to attack batters by looking at his average locations (pitches are my classifications, as above):
He locates the change arm side and the slider glove side, not surprisingly. His average pitch is located about average for a right-hander, and his fastball is a little high. Clearly, Claiborne is going for the strikeout and whiffs with the fastball, and not the groundball. Strikeouts are needed out of the bullpen obviously, but if a lefty can pull that fastball (it helps that he locates it slightly arm side like most righties), they can put it in the seats in the short porch at Yankee Stadium (it is tougher for righties to pull homers in that park, so going in on them with good fastballs is probably a good thing). This will make Claiborne's change very important. For him not being any kind of real prospect, I like Claiborne, and while he won't be any kind of elite reliever, if he can go one or two innings at a time and have the minimal platoon splits the release point suggests he should have, he can pitch in the big leagues for a long time.