Trevor Bauer’s Peculiar Curveball

Earlier today, Eno Sarris took a look at the arsenals of tonight’s World Series Game Two starters, Trevor Bauer and Jake Arrieta. In this article, I’m going to hone in on one of those pitches in particular: Bauer’s curveball.

Pitchers want to disguise their pitches. This is a pretty obvious statement – it’s harder for a batter to hit a pitch if he can’t tell what’s coming. So naturally, conventional wisdom dictates that pitchers should try to make every pitch look the same coming out of their hand. You don’t want drastically different mechanics while throwing one type of pitch than while throwing another.

So when Trevor Bauer throws his curveball from a significantly different height than all his other pitches, that stands out. It’s hard to notice on television, but Bauer releases his curve a full six inches higher than all his other pitches.


Or, here’s another way to look at it that highlights just how deviant the curve is from every other pitch:


It seems to me, a guy who struggled in Little League, like a pretty minimal difference — and something to which it’d be difficult to adjust in real time. But according to our prospects expert Eric Longenhagen, if a hitter sees a higher arm slot and knows that means curveball, they’re more likely to take the pitch – especially if they can tell that the ball is going to dip out of the zone. Bauer is facing major-league hitters: they perform their research and are prepared for what they’re facing, and they can adjust to tiny differences better than any other athletes in the world.

What’s more, in order to generate the higher release point, Bauer has to let go of the pitch earlier than he does others so that his arm doesn’t come down too much before he lets go. (It’s not like he stand on his tiptoes or jumps when he throws his curveball, and the extra height has to come from somewhere.) So the hitter has ever-so-slightly more time to track the pitch in the air. I don’t know if that’s very significant, but it can’t help the pitcher.


So, theoretically, this all should hurt Bauer. In particular, he should have a fairly low swing rate on pitches outside the zone (O-Swing%) on his curveball. Except…

Curveballs, 2016
Player O-Swing% SwStr% Contact% RV/C wOBABIP GB% Exit Velocity
Trevor Bauer 32.7% 13.9% 65.7% 1.4 .282 62.3% 77.9
MLB 33.1% 12.9% 67.8% 0.1 .362 46.1% 75.7

Instead of being poor, Bauer’s curve is extremely average to even above average across the board. Hitters can’t seem to square it up particularly well – he allowed just a .282 wOBA on contact and a pretty middling average exit velocity to go along with an elite ground ball rate. They don’t lay off it too much – yes, Bauer’s O-Swing% is slightly lower than average, but the difference is less than half a percentage point, hardly significant. His curve was worth +1.4 runs per 100 pitches (denoted by the RV/C column above), which is a very solid number.

The question is, then, why does Bauer’s curve work so well for him when it’s so easily identifiable? Well, even if a hitter knows what’s coming, sometimes a pitch can still be hard to hit. Mariano Rivera became the best closer of all time throwing the same pitch over and over; Kenley Jansen, Aroldis Chapman, and Zach Britton are similar; every knuckleballer works that way, too. The movement and spin on Bauer’s curve is fantastic – in fact, it stacks up well to a certain other notable right-handed curveball:

Notable Curveballs
Player Year(s) Horizontal Movement Vertical Movement Spin Rate Velocity
Trevor Bauer 2016 5.584 -10.029 1885 76.9
Adam Wainwright 2009-10 7.958 -8.662 1863 74.1
MLB 2016 3.505 -5.169 1330 77.7

Now, I’m not suggesting that Bauer’s curveball is on the level of prime Wainwright’s, or even that it could be if he fixed his release point: there’s a lot more that goes into a pitch (setting it up, tunneling, control/command, attacking the hitter’s weaknesses, etc.) than what I’ve mentioned. But the physical similarities help explain why Bauer’s curve can survive its lack of deception.

And to be sure, a poorly disguised pitch is hardly a death sentence. Out of 189 pitchers who threw 100 curveballs and at least 400 other pitches, Bauer has the eight-largest gap in average vertical release point between curves and non-curves – just about six inches – and the names surrounding him for the most part aren’t great. But there are some very successful pitchers, namely Max Scherzer and Clayton Kershaw, who fail to disguise their curveballs in a similar way.

Vertical Release Point Difference Between Curves and Non-Curves
Player Curveball and Non-Curveball Height Difference
Jon Niese 0.670
Brad Ziegler 0.599
Paul Clemens 0.586
Jorge de la Rosa 0.577
Joe Blanton 0.566
Joakim Soria 0.554
Max Scherzer 0.539
Trevor Bauer 0.482
Jeremy Hellickson 0.477
Miguel Gonzalez 0.472
Jake Odorizzi 0.460
Seth Lugo 0.454
Hisashi Iwakuma 0.452
Clayton Kershaw 0.450
Leaders, 2016. Values in feet.

First, this raises the question of whether Kershaw’s curveball could be even better that it already is, which is a terrifying thought. But more relevantly, it shows that Bauer should be able to maintain this success even with the release he has now. The list isn’t terribly inspiring, but it has plenty of bright spots. All in all, you’d rather more deception, but whatever works works.

Because, unfortunately for Bauer (and Kershaw and Scherzer), it’s not so easy to just make curveball better by hiding it more. Bauer has worked incredibly hard his whole life to refine his mechanics to get to where he is – every pitcher does, but Bauer especially – and there’s a reason he lets go of that curveball when he does. That location generates the best movement and spin, and switching it up might screw with that. It’s easy to point and say that Trevor Bauer’s curveball could be elite were he to hide it better, but all the internal interactions won’t necessarily allow it.

As Eno touched on in the earlier article, Bauer has suffered from command problems, so it makes sense that he would stick with the mechanics he has if they’re repeatable. This would make it particularly difficult for him to just magically drop his arm and keep the same movement and spin. But you wonder if it’s worth it to try.

We hoped you liked reading Trevor Bauer’s Peculiar Curveball by Jonah Pemstein!

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Jonah is a baseball analyst and Red Sox fan. He would like it if you followed him on Twitter @japemstein, but can't really do anything about it if you don't.

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Lucas Haupt

One thing to keep in mind with release points of guys with 12-6 type curves is that release points are recorded at 50 feet. So that point isn’t really where he releases the ball, it’s where the ball was 10 feet passed the rubber. So in a lot of these cases, he could be releasing the ball so that it is traveling upward at release point. Does that make sense to you?