It looks like Derek Holland will be anchoring the Texas Rangers' starting rotation this season. The left-hander has a nasty slider, by far the best pitch in his repertoire. He had a 36.0% strike out rate on the pitch last season, and opposing batters hit a measly .128 against it with a .234 SLG%.
One of the reasons Holland has been so successful with the pitch is his ability to locate it. Check out the pitch frequency on his slider last year:
Holland really came in on righties with the slider and managed to avoid leaving the pitch out over the plate. The only HR he yielded on the pitch last season was to B.J. Upton where it hung right over the heart of the plate. That one pitch had 4.6 feet per second of vertical movement, more than a foot less than he averages on his sliders.
Holland will really need to improve his fastball this season if he's going to have success in the Rangers rotation. While his slider was clearly his out pitch, his fastball gave him a lot of trouble. Righties really teed off on it, batting .355 off it with a .500 SLG% in 76 PA ending on the pitch.
Holland located his fastball over the middle of the plate far too often last season. If he can tighten up his control a bit more, he'll have a much easier time setting up his slider on hitters.