Caleb Thielbar’s Curveballing Comeback Came Courtesy of Low-Hanging Fruit

Caleb Thielbar didn’t come out of nowhere, but he did return from a form of baseball oblivion. A reliable reliever for the Minnesota Twins in 2013 and 2014 (103 appearances with a 2.59 ERA), the 33-year-old southpaw had spent all but six innings of the next five seasons in the minors or indy ball. His 33rd birthday fast approaching, he re-joined the Twins organization last December with designs on resurrecting a career that had regressed, then found itself stuck in neutral.

Thielbar’s return went better than many had expected. Featuring the game’s slowest curveball — a mesmerizing 68.8 mph on average — the Gopher State native fashioned a 2.25 ERA, and a 2.34 FIP, over 17 appearances covering 20 innings. A dark-horse contributor coming into the season, he instead was a godsend for the Minnesota bullpen.

He discussed the roots of his hiatus, and the reasons behind his successful return, in the final days of the 2020 campaign.


David Laurila: We first spoke during the 2014 season. How would you describe what’s transpired since that time?

Caleb Thielbar: “The five years in between my last appearance [on April 30, 2015] and being back this season was a lot of experimenting and trying to find what works. I went exploring. I drastically changed my workout routine. I drastically changed my throwing program. I finally figured out something that really worked, and was actually sustainable.”

Laurila: Five years is a long time. Were there times you questioned whether it was worth it?

Thielbar: “Oh yeah. Not so much in 2015, but that next year I couldn’t get a job and was in indy ball. I started to feel good again, had a really good summer, and got picked up by the Marlins. But then they released me in spring training. That was kind of the time where I was like, ‘You know… I don’t know.’ But I had trained the whole winter, so I decided, ‘All right, I’ll go play indy ball again and see what happens.’ Then I ended up straining an oblique about halfway through the summer, and once again kind of thought that might be it.”

Laurila: How had you gone from being a quality big-league reliever to out of affiliated baseball?

Theilbar: “My shoulder. I had some bicep tendonitis starting about midway through 2014, and it just wouldn’t go away. It kind of lingered all through 2015. It’s pretty easily explainable. My elbow height relative to… I guess you’d call it my shoulder abduction, was way too low. It caused way too much strain on my shoulder, and my bicep tendon would just get inflamed.

“Once I discovered Driveline and did some of their drills — pivot picks, in particular — really helped me get my shoulder more on plane. All of a sudden my shoulder started to feel better and the velocity started to come back. I was healthy again. I guess that was the main thing.”

Laurila: When did you discover Driveline?

Thielbar: “I think it was after the 2015 season. One of my friends went out there. He was he was from Ohio, so he stayed at my house on the way out, and again on the way back. We talked for hours about what he did, what he thought of it, and it kind of sold me. I started looking into it, and after that 2016 season when my arm started feeling good again is when I started to hit it really hard. My velocity was probably as high as it’s ever been going into that spring training with the Marlins, but then it just fell apart. I couldn’t figure anything out anymore.

“I was still getting back to being sustainable at that time. I’d only done it for a couple of months, so it’s not really surprising that I kind of fell apart. Once I got back into it, and was doing it for a year or two, is when the changes started taking place permanently.”

Laurila: Who is the friend that told you about Driveline?

Thielbar: “His name is Brian Garman. He actually coaches in the Reds system now. He’d been in the Brewers system for a couple years, ended up having some shoulder problems, and went out to Driveline kind of as a last resort. His [shoulder] was too far gone at that point, but he really liked what they did.”

Laurila: Your primary breaking ball used to be a slider, and now it’s a curveball. When did that change rake place?

Thielbar: “Last year. I’d gotten off to a not-very-good start in Triple-A, so I went to my pitching coach, Juan Nieves, and said, ‘We’ve got to figure out what’s going on.’ We started looking through all my pitches individually — what I was throwing, where I was throwing them — and discovered that the small amount of curveballs I’d thrown so far that year weren’t getting hit. So we were like, ‘OK, let’s throw more of them and see what happens.’

“Basically, I rattled off the three best months of my career. I mean, it was really a simple thing. It was just looking at the numbers and seeing that it wasn’t getting hit, so maybe I should throw in a lot more. That’s what we did.”

Laurila: Did you look solely at the results, or also at the movement profiles?

Thielbar: “We really just looked at what the hitters were doing with it, in part because I don’t like to mess with stuff too much during the season. But I guess the work I’d done with Rapsodo was kind of paying off; I just hadn’t realized that it was a good pitch. When I had been in the big leagues, and before that on my way up through the minor leagues, it was more slider than curveball. A lot of that was due to me not having the best command of it back then, but it also wasn’t quite as good of a pitch. That’s kind of changed, I guess.”

Laurila: So your curveball has gotten better…

Thielbar: “Yes.”

Laurila: Exactly why, and how, did that happen?

Thielbar: “Honestly, it’s pretty low-hanging fruit. It was just looking on Rapsodo and trying to improve the spin efficiency of it, and therefore the break. I mean, I’ve always had the big 12-6 curveball, and it’s always been basically the same speed no matter how hard I throw. But after I saw it on a Rapsodo for the first time, it was like, ‘OK, now we can actually quantify things.’ We could look at it and see if it’s possible to make it better.

“It was a matter of manipulating my hand just a little bit better, and being able to get completely on top of it, to get close to 100% spin efficiency rather than 80%. That’s a pretty big difference, break-wise, and you just don’t see it with the naked eye. So there wasn’t anything super crazy. It was basically trying to improve on a pitch that was actually pretty good already. It wasn’t that hard for me to do, honestly. Being a high-arm-slot guy, it’s a little bit easier to get on top of a curveball than it maybe is for some other guys.”

Laurila: It sound like there wasn’t a grip change, per se.

Thielbar: “No, I didn’t really change much there. I throw with the same grip that basically everyone with a good curveball has. If you look around the game, guys like Clayton Kershaw, Rich Hill, Sandy Koufax back in the day — specifically lefties — we all have the same grip. It’s more of what you can do with it.”

Laurila: Fastball-wise, you’re only throwing four-seamers now…

Thielbar: “Yes, I got rid of the two-seam last year. I never really had much command of it anyway, so it was kind of an easy decision. It also didn’t have anything special for movement; it never had that true, lefty two-seam action that everyone always loves. No matter no matter what I did with it, it just wasn’t a very good pitch for me.”

Laurila: You’re working with Twins pitching coach Wes Johnson now. What has the emphasis been with him?

Thielbar: “It’s been a lot about the sequencing mindset, and confidence. There is some mechanical stuff that I want to talk to him about after the season. Like I said, I don’t like to mess around too much in-season, because that’s when I get myself in trouble, but I’d like to work on perfecting certain things. I’d also like to see about adding some velocity.”

Laurila: Your average fastball velocity was 90.1 mph.

Theilbar: “Yes, it’s been down a little bit this summer, I’ve been very frustrated about that. Last year it was up — I had the highest velo of my career — and this spring it was really coming back, but then we had to shut down. I was able to keep throwing a lot, but it wasn’t the same as getting consistent outings and being able to maintain game feel. Then, having that shortened summer camp, I was just never able to get back to where I want to be.”

Laurila: Being a left-handed reliever who doesn’t rely on velocity, but rather a plus curveball and an ability to keep hitters off balance, you profile as a guy who might pitch until he’s close 40 years old.

Thielbar: “It’s possible, but I have a lot of velocity left in in me, too. And I know what the problem is, I just don’t know how to correct it right now. But like I said, I’ll be talking to Wes, and I’ll also be going back out to Driveline, so hopefully I’ll get some ideas about how to correct that. There are a couple more miles-per-hour in there, I just need to figure out how to physically get to them.”

Laurila: Is the difference between 90-91 and 92-93 really all that meaningful?

Thielbar: “No it’s not. But it sure helps. I don’t think it’s a secret that teams love velocity — and for obvious reasons: there’s more margin for error. Plus, it’s way more fun to throw harder.”

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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3 years ago

Another good interview, David. I always look forward to your articles.