Adam Cimber Slides to the Left

You’ve probably seen Adam Cimber pitch before. It looks strange, like this:

Or fine, maybe you haven’t seen Cimber himself, but you’ve seen someone like him. Righty, low arm slot, baffles same-handed hitters despite an eight-handle fastball (that’s one with an average velocity in the 80s, for those of you who don’t speak obscure bond market jargon).

As you’d expect, Cimber has been far better against same-handed batters in his career. It’s not particularly close, either; he’s allowed a .315 wOBA to lefties compared to just a .275 to righties. That’s just the name of the game when you’re a soft-tossing sidearmer. Batters who get a good look at your delivery will give you fits.

There’s another reason that sidearmers don’t fare well against opposite-handed batters: Their arsenal just doesn’t match up very well. If you can think of one of these pitchers, they probably throw a predictable mix of fastballs and sliders. It’s simply the natural arsenal from that arm slot. You can run fastballs in and mix in sliders that start out headed for the batter’s hip before ending in the opposite batter’s box.

Cimber is no exception. His pitch mix is exactly what you’d expect: 65% fastballs, 35% sliders. Sliders historically demonstrate platoon splits; in every year since pitch tracking data began in 2008, right/right sliders have produced better results than right/left sliders, whether you care about whiff rate, wOBA, or run value per pitch. That’s why pitchers throw far fewer sliders when they’re at a platoon disadvantage:

Most pitchers replace those sliders with changeups. That’s a problem for Cimber, as he doesn’t have a changeup to fall back on. When he came into the league, he followed convention in an attempt to solve that problem, throwing a ton of fastballs in place of those sliders. In 2018 and ’19, his first two years in the majors, he threw his slider 33.2% of the time against righties, and only 15.2% against lefties.

That plan worked about as well as I’d expect, which is to say not well at all. He allowed a .407 wOBA against left-handed batters, and even though you should regress the numbers somewhat (he only faced 150 of them), it was still ugly. If you use a rule of thumb I cribbed from The Book, the average righty pitcher allows a wOBA 5% higher against lefty hitters as compared to righties. Even after regressing Cimber’s numbers toward the mean with 700 plate appearances of league average platoon splits, he allowed a wOBA 13% higher against lefties. Again, this makes sense – he’s a sidearmer without a changeup.

How has he done against lefties since then? I’m glad you asked – he’s been absolutely nails. He’s faced a lefty 144 times since the start of 2020, and he’s allowing a .221 wOBA against them, as compared to .282 against righties. Now he’s a strong reverse platoon pitcher, and even using the same regression toward the mean, that comes out as roughly an even split pitcher. You don’t have to believe it – he’s been quite lucky in terms of home runs per fly ball against lefties, for example – but on results alone, Cimber looks like a completely different pitcher against lefties.

How did he do it? Naturally, he started throwing his slider more. As I mentioned up above, he came into the league throwing sliders to lefties 15.2% of the time. Over the last three years, that number has ballooned to 40.7%. That’s nearly triple the old rate, and a higher slider usage than he threw to righties from 2018 to ’19. In fact, he’s only used his slider against righties 30.6% of the time since the start of 2020; his slider usage there is declining.

Pitching backwards is supposed to mean throwing offspeed pitches in fastball counts and vice versa. Cimber is pitching upside down; he’s treating lefties like righties and vice versa, and it’s working. Cimber isn’t exactly the only one doing this, but he’s the most extreme example by a mile. His slider usage goes up by 26.7 percentage points in 2022 when he’s facing an opposite-handed batter. Humberto Castellanos increases his own slider usage by 21.6 percentage points the opposite way; no one else with 100 sliders thrown in 2022 checks in above 15 percentage points.

Cimber is doing it to replace his sinker. That sinker is his bread and butter – against righties. It generates grounders at a phenomenal rate, and he throws it 60% of the time. He doesn’t like the pitch against lefties, though; he’s thrown exactly three sinkers to them in the past two years. Perhaps it’s a swing plane issue, perhaps the pitch is just easier to track when you look at it from the lefty batter’s box, but whatever the reason, he sticks to four-seamers against them.

Just one problem – having your pitch mix rely heavily on a four-seam fastball that doesn’t crack the 90 mph barrier is a recipe for disaster. Between four-seamers and the odd sinker, Cimber was throwing 83% fastballs to lefties in 2018 and ’19, and getting tattooed for his trouble. Being fastball-only, with a low-velocity fastball and without the platoon edge, simply wasn’t working for him.

Sure, sliders are worse against opposite-handed hitters, but so is only throwing slow fastballs, so Cimber made the change to rely on his slider. And what do you know – mixing up his pitches made it harder for lefties to tee off on his fastball.

Here’s a secret about sliders: even though they demonstrate a platoon split, they’re still a better pitch against opposite-handed pitching than fastballs are. Don’t believe me? I’ve got receipts. Here’s a table of how right-handed sliders have done against batters over the pitch tracking era, split by handedness:

And here are fastballs:

Both pitches get worse when thrown to lefties, but if you look closely, you’ll notice the platoon splits are roughly equal. Whether you’re throwing a fastball or a slider, lefties do better than righties against it, and that improvement is by roughly the same amount regardless of pitch. Changeups don’t fit the mold, which is why so many pitchers use them as an equalizer – but if you don’t have a changeup, there’s no reason not to stick with your breaking pitch regardless of who’s at the plate. The overall results are better, even if they both decline when you don’t have the platoon edge. Just like pitching as a whole has been a march away from fastballs in the past 10 years, Cimber is moving away from fastballs and towards bendy stuff, even if that goes against the rule of thumb he’s known since he was a kid.

When a hitter gets to sit on a fastball with no outstanding traits, they’ll generally tattoo it. In 2018 and ’19, 41% of the balls that lefties put into play against Cimber’s fastballs were in what Baseball Savant calls the “sweet spot,” between eight and 32 degrees. That’s low line drives, line drives, and fly balls that carry. That’s extremely not where you want to live as a pitcher; balls hit at those launch angles have produced a .685 wOBA this year (that’s a .582 batting average and a 1.035 slugging percentage).

So, yeah… the key to Cimber’s game is not letting lefties tattoo his fastball. A good rule of thumb is that pitchers help influence launch angle while batters provide the thump, and Cimber’s sinker is a great example of that; it runs a juicy 66.7% groundball rate. His four-seamer checks in at 37%, and he also allows more line drives than you’d like. Line drive rate for pitchers isn’t particularly sticky, but there’s some skill to it, and throwing a slow pitch that moves exactly how batters expect is a good way to elevate your line drive rate.

A good way to elevate your fly ball rate? Throw an upside-down slider! Cimber’s slider is the opposite of his sinker in more ways than one. It has strange, upward break thanks to his low delivery, which means it generates fly balls like you wouldn’t believe. In fact, it generates popups like you wouldn’t believe; in his career, the pitch has a 34.6% infield fly ball rate, which means that more than a third of the fly balls he induces with his slider are near-automatic outs.

He’s gotten even better at it this year, thanks to a change in pitch shape. His slider falls 2.5 fewer inches than it used to on its path to home plate, which means batters are getting under it more than ever. That pesky sweet spot rate is down, his free outs thanks to popups are up, and regardless of how you look at it, he’s performing better against lefties than ever before.

Another way of thinking about it: per Alex Chamberlain’s pitch comparison tool, Cimber’s slider is one of the best pitches in baseball, period, when it comes to inducing higher launch angles by hitters. His sinker is one of the best at inducing lower launch angles. Very high and very low aren’t dangerous; that’s where outs live. His four-seamer? It’s smack dab in the middle, with little impact on launch angle whatsoever. Combine that with its middling velocity, and you can see why an all-fastball diet wasn’t giving lefties indigestion.

In some ways, what Cimber is doing is a refutation of conventional wisdom. “Throw your breaking pitch less often to lefties” is a rule that right-handed pitchers have lived by. Cimber himself lived by it earlier in his major league career. But at the same time, his new pitching approach is a triumph of common sense. Would you rather throw the low-velocity fastball that moves like a more normal arm slot pitcher’s sinker, or the UFO breaking ball that rises and flits towards lefties like a hummingbird in search of nectar?

When you put it that way, it’s an obvious decision, and the Jays seem to agree. It’s not a sea change, but he’s facing lefties more often than he did earlier in his career over the past two years:

Is this the new normal for Cimber? I think so. It just makes too much sense not to be, unless he can develop a changeup and wants to change things up. In the meantime, he’s going to keep defying conventional wisdom, and it’ll probably keep working. After all, Cimber is anything but conventional; he throws a slider that rises, and building his game around his unique pitches rather than trying to conform to the rest of the league continues to pay dividends. It might not follow a simple heuristic, but it’s hard to argue with success, and Cimber has a 2.20 ERA (and 3.16 FIP) over the past two years. He’s nothing but successful, even as he pitches nothing like anyone else in the majors.