Trevor Bauer and the Lost Screwball

Trevor Bauer is a lot of things – former first round pick, pupil of Ron Wolforth’s unique coaching style, permanent breakout candidate, and now part of a rotation in Cleveland that many predict will be one of this year’s best. Bauer is a part of the current and future plans for Cleveland, but he’s also a work in progress: a not yet fully realized starter that suffers from real control problems on the mound. The most intriguing thing about Bauer isn’t his upside, however — it’s the fact that he throws a pitch almost totally lost to the modern game: the screwball.

Today, we’re not going to speculate on what Bauer might accomplish this year. Instead, we’re going to focus on the screwball, a pitch thrown by just one or two other pitchers in the majors. It’s an exceedingly rare pitch, and we’re going to look at how he throws it, and see where it fits in his arsenal.

First, we’ll turn to a GIF created from Bauer’s YouTube channel, where he posts videos with multiple camera angles of him throwing all his pitches (with great explanations). Behold, the screwball, which he calls a “reverse slider”:


If you’re unfamiliar with screwballs, the first thing you’ll notice is the way the arm rolls counter-clockwise (for a RHP) inward toward the body as the ball is released, which gives it unique arm-side run and sinking action. That movement is contrary to almost every other pitch thrown, and it’s a big reason why the pitch has fallen so out of favor: there’s a widely held (though largely unsubstantiated) belief that throwing them causes injury due to the “unnatural” arm motion. Whether screwballs cause injuries or not, they’re weird, and not many pitchers even attempt to throw one in their lifetime.

Trevor Bauer, however, does throw one, and that’s incredibly interesting before we even factor in the pitch’s traits and effectiveness. So how effective is it, and what does it actually look like? To answer those questions, let’s begin by plotting it in the zone alongside his other pitches:


From the catcher’s perspective, we can see the screwball has a little bit more arm-side run and sink than the changeup. Looking at the velocity data, what’s unusual about Bauer’s screwball is that he throws it very hard: it averages about four MPH faster than his changeup (88.4 vs. 84.6 in 2014, respectively). Usually, the velocity difference is the other way around, with the screwball coming in slower than the changeup.

Now that we know how it acts on paper, let’s see the pitch in practice to get a feel of what it actually looks like. I searched through a few of his starts and ended up picking a couple pitches from June 11th, 2014 against the Royals. They clock in a little below the pitch’s average velocity for the year, but they’re a good showcase of what’s going on with his approach:


The first pitch, to Billy Butler, is supposed to be down and in, and it seems intended to induce a groundout to the left side of the infield. It’s not a terrible pitch (especially because Bauer is ahead in the count), and there’s some nice run and sink to it — Country Breakfast just isn’t interested. The second pitch, to Jarrod Dyson, is supposed to be down and in as well. Bauer misses, though there’s enough tail to get Dyson to foul the ball into the seats. Bauer’s approach with his screwball is pretty clear from these two examples and its usage in other starts: get hitters out in front for groundouts and weak contact.

After taking into consideration the action, velocity, and usage of the pitch, the crux of the issue with Bauer’s screwball is that it isn’t much like a screwball. What’s telling is that he calls it a “reverse slider”: in essence, it’s really a power pitcher’s interpretation of a screwball. The pitch acts more like a slow two-seam fastball or faster changeup, which seems superfluous given Bauer’s good speed differential between his 95 MPH fastball and 84 MPH changeup: it’s not slower enough from his other offerings to generate swings and misses, and doesn’t have enough movement and control to generate consistent weak contact for easy outs.

That lack of control is something all of his pitches suffer from. Bauer’s screwball might be a weapon if he learns how to spot it, but currently it generates below-average whiffs (under 9%), a terrible ground ball rate (6%), and suffers from bad control: he hit four batters with his screwball this year, just one shy of how many he hit with his fastball. The ratio of fastballs to screwballs Bauer threw in 2014? 12:1.

Bauer’s usage of the screwball might be the big indicator of where it stands in his arsenal going into the season. After 2013, in which he threw the pitch 22% of the time in limited appearances, he only threw the pitch 3% of the time to LHH and 5% of the time to RHH in 2014, indicating it may be on the way out. That’s a shame: I’d like to believe the “power screwball” might have a place in this world. However, regardless of whether it survives or not, we always have Hector Santiago:


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Owen Watson writes for FanGraphs and The Hardball Times. Follow him on Twitter @ohwatson.

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Sandy Kazmir
Sandy Kazmir

As always, Nathaniel Stoltz is terrific:

I love when the Rays bust out the “Phantom Cam” but man does it look like Alex Cobb, among others, is going to shred his arm with how much pronation he gets on the ball. It’s not a screwball, it’s a two-seamer, but dang does he get that thing to run. Much like we’ve seen greater clarity between the slider and the cutter due to Pitch F/x I wouldn’t be surprised if see more guys amping down their two seamer to get more run and turn it into a true screwball.

Nice read, thanks for taking the time, Owen.