Felipe Paulino’s Fastball

And I’ve been putting out fire / With gasoline – David Bowie, Cat People

If Felipe Paulino qualified for the ERA title, his 95.1 MPH fastball velocity would rank second in all of baseball among starters. Felipe Paulino’s 95.1 MPH fastball might be what stands between him and future success.

Paulino has long been a head-scratcher. His career ERA (5.48) matches neither his career FIP (4.27) nor xFIP (4.03), and once you delve into the components, he doesn’t become any easier to understand. He’s struck out over eight batters per nine on the strength of an above-average swinging strike rate. He’s walked batters at a slightly-above average rate, but he’s also managed an average ground-ball rate. And then there’s the gas he pumps out of his right arm.

It might be the gas, and the arm, that is hurting his attempt to fight fires. While it’s easy to say that his .344 career BABIP can’t hold, and that his career 64.6% strand rate must get better, it can’t all be luck. Not 217 innings in. If we start with his platoon splits, some interesting trends emerge.

He’s been terrible against lefties. While he has strong numbers against same-handed batters (3.69 FIP, 3.68 xFIP), the 27-year-old righty has poor ones against lefties (5.13 FIP, 4.54 xFIP). His BABIP against lefty batters is .377 over his career. His control is bad — he walks more than five left-handed batters per nine, or twice as often as he walks right-handed batters — but the BABIP suggests that there’s something very hittable about his repertoire.

Platoon splits on pitches help us out further. Work by Max Marchi built on work by Dave Allen has pointed out that the platoon splits on fastballs are not created equally. The fastest fastballs, or heaters, have the highest platoon splits in the group. Sliders have always been known to have platoon splits. In two-strike counts this year, Paulino has used those two pitches over 90% of the time.

But Paulino’s fastball has suffered worse than the average heater. The lowest full-year BABIP he’s allowed on ground balls off his fastball is .379. That’s the lowest. The number across baseball is .251. Even if you go with the BABIP that lefties have hit off of righties on four-seam fastballs, you can’t push the league BABIP over .263. The sample size on this is small — only 50 lefties have put fastballs in play on the ground. Still. Why are batters hitting .460 on fastballs they put in play on the ground off of Paulino? What can he do about it?

David Goliebiewski pointed out that some of his success this year has come from using his curve and change more against lefties. But the fastball is the most-thrown pitch in the game, and Paulino won’t be able to completely drop it against lefties. The answer may lie in his heat maps. Let’s up the sample and check out where his fastball sits against lefties over the past two years, compared to where it sits against righties.

Yeah. It really looks like he needs to get that pitch down a little. Way too many down the heart of the plate, and in general his pitches to lefties are higher. There could be other explanations, but by the average movement values, his pitch isn’t extremely straight. The stuff seems to be there, and obviously the velocity is there. And his ability to keep the ball in the zone is not terrible. So it really could be something like his ability to put the ball exactly where he wants it in the zone that is lacking.

We aren’t pitching coaches or firefighters here, but we can say that throwing a 95 MPH fastball down the pipe is probably like fighting fire with gasoline. Not very effective. Felipe Paulino has plenty of promise, but much of his struggles to date can be blamed on location as much as it can be blamed on poor luck. Perhaps a little confidence will allow him to improve his command and place the ball better within the strike zone.

Thanks to Harry Pavlidis for some of the numbers in this story.