DJ Herz, Aaron Loup, and Trevor Williams on Learning and Developing Their Changeups

The Learning and Developing a Pitch series returned this summer after being on hiatus last year due to the pandemic. Each week, we’re hearing from three pitchers on a notable weapon in their arsenal. Today’s installment features DJ Herz, Aaron Loup, and Trevor Williams on their changeups.


DJ Herz, Chicago Cubs prospect

“It was 2020 spring training and I was in the pitch lab. [Cubs pitching coordinator] Casey Jacobson was with me. I threw my regular four… I never had a changeup going into pro ball. So, I threw it off my four-seam grip, and it wasn’t bad, but it wasn’t good, either. It was too firm, only about four miles off my fastball. Casey had me try another grip, and again it was just all right. Then, the second grip we tried was kind of Vulcan-ish.

DJ Herz’s changeup grip.

“I put it deep into the wedge between the middle and ring finger. I‘ve got the middle finger off the two-seam grip, so I can just rip down on it. I mean, the first pitch I threw like that, it was like, ‘All right, let’s stick with that one; that’s the pitch right there.’

“I went back home and just kept throwing it. I’ve always been told that the changeup is one of the hardest pitches to learn. I was determined. I said, ‘Man, I want to learn this pitch so much.’ I’d hear these interviews with guys saying that having a good fastball and a good changeup is an awesome combo, so I would throw that pitch every single day. I’d long-toss with it sometimes. I kept working on it, and it’s paid off, man.

“I get a little arm-side run on my fastball, so I’m kind of already pronating a little bit. When I got this changeup grip in my hand, I was able to just pronate off of it. It was getting a lot of run — even more than on my fastball — and it was dropping. It looked like a fastball and the last second it would drop off the table. I remember Morty [Myrtle Beach pitching coach Clayton Mortensen] telling me that it’s like a helicopter pitch: it spins on a nine-degree axis. It’s spinning sideways, I guess you would say, like a screwball, or kind of a reverse slider coming from a lefty. Ever since the first time I threw it, I was like, ‘Damn, this thing is money.”

“I usually spin it 2,300-2,400 [rpm] and I think I got a couple this year at 2,500, kind of Devin Williams-ish. So that ball is spinning, and the good thing is that it’s spinning so much that it’s hard to pick up, because it’s spinning sideways. The spin efficiency has it looking kind of like a normal fastball, but again, it’s dropping off a table at the very end. I’ve been throwing my changeup as a swing-and-miss, like this is my go-to swing-and-miss — a strikeout pitch.”


Aaron Loup, New York Mets

“I’ve thrown a changeup basically from whenever I started pitching; it just kind of correlated over when I started throwing sidearm. But it’s definitely a little different. Being over the top, you’re more behind the baseball when you’re throwing it, but still trying to pronate. When I got sidearm, I had to… I used to basically throw a circle change, with the pinky on the side. Being sidearm, coming this way, I couldn’t get that ball to come out. I kept yanking them. So I had to move the pinky up, which basically allowed the ball to come out [rotating correctly].

Aaron Loup’s changeup grip.

“Moving my pinky [closer to the ring finger] really has no effect. It just sits up there. But being down here, it wasn’t allowing me… I couldn’t turn the ball over without yanking it. Resting it up there allows the ball to come out freely, which gives me that sinking, running, two-seam action. I’m more or less telling myself to make sure to put the circle out front when I throw it, and then it’s just kind of naturally finishing with pronation.

“It took a little bit of time to figure out at first. I kept throwing it how I used to normally always throw it, and could never get it over the plate for strikes. It was always inconsistent. Finally, I just started playing around with different things and was like, ‘You know, what if I just move my pinky up?’ That ended up fixing it.

“The velocity has probably been around 10 off my fastball for my whole career. As far as action-wise, I want to say the vertical is anywhere from -3 to -6, and the horizontal is usually 18-19.

“I don’t look too deep into [technology]. For instance, I’ve seen guys use [an Edgertronic], but I’ve never tinkered around with it too much. I like to stay simple. ‘Simple and stupid’ is what I like to say. As long as it’s working, and we’re having success, I don’t mess with it. When I’m pitching well — like this year — the changeup has typically been a big pitch for me.”


Trevor Williams, New York Mets

“I learned a changeup before I learned any breaking balls. It’s easier to throw, and I was pretty young. When you have little hands it’s easier to grip a ball with three fingers — a four-seam, three-finger changeup. In college, I started throwing it a little differently, because I had one breaking ball and needed to utilize another off-speed pitch. I messed around with different grips to try to make it sink, make it run, make it straighter. That’s really it.

“At that point there wasn’t [any technology involved]. It’s basically just going off the feel, and whoever you’re playing catch with — what they’re telling you — and the hitters in the box tracking your pitches. Stuff like that.

Trevor Williams’ changeup grip.

“In college, it was more of a traditional four-seam grip — not a circle, but four-seam straight. I tuck my thumb under on all of my pitches, so the circle never made sense to me. I’d say it’s the same now as in my first, or maybe second, year of pro ball.

“[From Rapsodo] I see how it mirrors behind a four-seam, behind my sinker [and] the way it looks best paired with my curveball or my slider.

“There’s not a lot [of pronation]. For me, it’s just a hint, a thought-process. If pronating makes you more comfortable with it, then great. But it doesn’t necessarily help for me. The spin is very average. Basically, I’m just trying to make the pitch look as much like my fastball as possible. In my hand, I want everything to feel the same as on my fastball, just [with a different grip].

“Something that helped me when I was younger is that I would curl my toes on my push-off foot. I don’t do that any more, though. Some guys think ‘land shorter.’ Some guys… whatever makes it more comfortable for them — if that’s over-pronate, if that’s extension, if that’s finger pressure, etcetera.”


The 2021 installments of the series can be found here.

The 2019 installments of the series can be found here.

David Laurila grew up in Michigan's Upper Peninsula and now writes about baseball from his home in Cambridge, Mass. He authored the Prospectus Q&A series at Baseball Prospectus from December 2006-May 2011 before being claimed off waivers by FanGraphs. He can be followed on Twitter @DavidLaurilaQA.

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