Patrick Corbin’s Electric Slider is Back

If you’re a nostalgic fantasy baseballer, you’ll remember that Patrick Corbin generated 3.5 wins above replacement (WAR) in his first full season of baseball before suffering the dreaded curse of Tommy John. (If you’re even more nostalgic, or more likely an Angels fan, you’ll remember he was traded alongside Tyler Skaggs for Dan Haren.) Corbin returned to baseball in 2015, and he shoved, seemingly indicating he suffered no ill effects of his surgery.

Yet 2016 was an unmitigated disaster, culminating in a midseason move to the bullpen and a full-season 5.15 ERA. A low strand rate (LOB%) is the blame — virtually no one suffers a 64.8% strand rate for a full season without some bad luck — but poor control and a home run problem complicated things. It appears to me Corbin ran afoul in two distinct ways in 2016.

It also appears to me he may have recalibrated himself. In his last three starts, he has struck out 23 and walked only four across 19.1 innings, good for a 1.86 ERA / 2.53 xFIP / 2.59 FIP.

The first issue, of primary interest to me, concerns his slider usage then and now. It’s back. Corbin had thrown his slider roughly 29% of the time upon returning to Major League action in 2015 — a departure from the strategy that drove his success in 2013, which resulted in even more K’s. For good reason: his slider is bread-and-butter pitch, the only one that accrues double-digit whiffs. Yet that fails to adequately characterize it. From 2012 to 2016, no pitcher who threw as many sliders as Corbin recorded a higher whiff rate (SwStr%) on the pitch. Not Clayton Kershaw, whose slider trailed by 0.8 percentage points. Nor Corey Kluber‘s, whose trailed by 1.5 percentage points. Relax the restriction to 1,000 sliders and only Carlos Carrasco’s is better. Further relax it to 500 and Noah Syndergaard rises to supersede them, but that’s it. Surely, you catch my drift.

Last year, though, Corbin seemed to abandon his slider. He proceeded with a sinker-heavy approach, one that generated a good deal of ground balls but few whiffs. He moved away from this unsuccessful pitch portfolio as the season wore on toward something that more closely resembles his current usage composition.

That shift, however, did not come without complication. I’m no mechanics expert, nor am I an actual mechanic, but something got all out of whack for Corbin:

That is a distinct change in horizontal release point, and it coincides almost perfectly with when his walk rates got completely out of hand, ballooning to 11.9% in July and 11.1% in August. Perhaps it’s no coincidence, then, that when Corbin rediscovered his arm slot, he rediscovered his command, cutting his walk rate in half in September.

It’s 2017, and Corbin’s release points look good. That, and he’s using his slider increasingly more often (almost 40% of the time!) with increasingly more success (almost 30% whiffs!). It’s hard to get by with one pitch, but his other offerings have their merits, either in the form of decent whiff rates (four-seamer) or solid ground ball rates (sinker). It may not be enough to ever make him more than a mid-rotation guy, but that’ll do in many fantasy leagues.

In the unfriendly confines of Chase Field, it might behoove Corbin to take a contact-management approach by ramping up his sinker usage to the credit of ground balls and the debit of whiffs. With only one true wipeout pitch, his margin for error is a bit slimmer. But if he can either get ahead in counts to set up his slider or induce (relatively) weak contact with his sinker, then perhaps he stands to see some gains.

Regardless, Corbin seems to have returned to form. I’m reluctant to buy into small-sample breakthroughs, but when they’re fueled by mechanical fixes and substantiated by a player’s own historical context, they warrant attention. Corbin’s slider was already one of the game’s best. He’s taking the Matt Shoemaker road to success: optimizing by simply throwing his best pitch most often (for Shoemaker, it was his splitter).

If Corbin can generate a 10% whiff rate each start on his slider alone, he will create success for himself, as he has done the last week and a half. He’s also pairing it with a superb 69.7% first-pitch strike rate (F-Strike%). For a man with a slimmer margin of control than the front-of-the-rotation guy we once thought he might be, he certainly allows himself additional wiggle room by getting ahead in counts and more frequently flashing one of the best put-away pitches in the game.

That is, if he can simply return to something like 8.0 K/9, 2.5 BB/9, 50% ground balls — something he looks poised to do after his slow start — it will suffice, even in some shallower formats. Chalk him up as an early comeback candidate.

(If you are an Arizona local or avid Diamondbacks fan and you have read or heard anything about mechanical adjustments Corbin may have made, please leave a comment. I’m curious to know what else is floating around that I couldn’t find.)