If you’ve been reading the site for a while, you’ve probably figured out that I like groundball pitchers. Due to the emphasis placed on strikeout rates as a predictor of future success, too many sinkerball strike throwers have been overlooked as prospects on their way to success on the majors, and too often, their ability to get outs is dismissed as a fluke because they don’t generate an above average amount of swinging strikes. However, when you see guys like Aaron Cook, Jake Westbrook, Paul Maholm, and John Lannan consistently keep runs off the board, it becomes easier to realize that there’s a path to success that doesn’t involve high strikeout rates.
However, there’s a downside to being an extreme groundball pitcher. Most of the guys who rack up tons of groundballs rely heavily on their two seam fastball, and as Dave Allen showed with Pitch F/x data, the two seamer has the largest platoon split of any pitch in baseball. It is a terrific pitch against same-handed hitters, but it’s not much of a weapon against opposite handed hitters. Scouts have intuitively known this for a long time, which is why so many sinker-slider guys gets pigeonholed as relievers, where they can be used in situations where the platoon problem can be minimized.
If a groundball pitcher has a good change-up (or split finger, or even a curve in some cases – vertical movement is the key), he can neutralize opposite handed hitters and be an effective starting pitcher. However, without that off-speed pitch, he’s probably destined for the bullpen or a Vicente Padilla career path (check out his career L/R splits some time).
So, all that said, this post is actually about Chad Jenkins, the Toronto Blue Jays first round pick in last week’s draft. Jenkins was one of the more interesting pitchers in the draft for me, because I’m really curious to see how well his repertoire translates to professional baseball. The scouting report on him gives him a 90-94 MPH heavy sinking fastball, a potentially plus slider, and an average change-up. Given those pitches, we’d expect him to be a groundball guy with potentially a platoon problem.
Thanks to the work of Kent Bonham and Jeff Sackmann, we have split data for college players. How well does the data line up with our expectations based on the scouting report?
Vs RHB: 56 2/3 IP, 1.27 BB/9, 11.28 K/9, 1.75 G/F
Vs LHB: 28 1/3 IP, 2.22 BB/9, 7.62 K/9, 1.72 G/F
He destroyed right-handed bats, holding them to a .200/.230/.259 mark, but wasn’t nearly as good against lefties – .287/.341/.344. He still managed to get LH hitters to pound the ball into the ground, but his fastball/slider don’t work as out pitches against opposite handed hitters, and his change-up looks like it could use some work, based on both the scouting report and the data.
The Blue Jays love groundball pitchers almost as much as I do, but the ones they’ve had success with have developed good secondary stuff. That’s going to be the key for Jenkins as he gets into Toronto’s system. If he can refine his change-up and make it a real weapon against lefties, he has a chance to be one of my favorite pitchers in a few years. If he can’t, I hope he likes hanging out in the bullpen.
Dave is the Managing Editor of FanGraphs.