How D-Backs Prospect Matt Tabor Learned a Bullet Slider

Matt Tabor is well-regarded primarily because of his fastball and his changeup. The latter, which he throws with a Vulcan-like grip, is his best pitch. The former, which gets solid ride but lacks plus velocity, is delivered with above-average command. Last year, the 21-year-old right-hander walked 16 batters, fanned 101, and logged a 2.93 ERA over 95.1 innings with the low-A Kane County Cougars. Bumped up two slots following Monday’s Starling Marte trade, Tabor currently ranks 11th on our Arizona Diamondbacks Top Prospects List.

His slider, a pitch he didn’t throw in games two summers ago, has become an important weapon for the 2017 third-round pick. Tabor credits Carson Cross with spurring its development. The two were together at PowerHouse Sports New Hampshire shortly before Cross took a job in the Milwaukee Brewers organization last February.

At the time, Tabor was a two-pitch pitcher. A third was needed, and to that purpose he was at wit’s end.

“Mentally, I was just so screwed up,” the Westford, Massachusetts native admitted. “I had pretty much convinced myself that I could never throw a good slider. I’d messed around with a lot of things, but it was still loopy and popped out of my hand. In high school, I could just flip that shit over and it was going to buckle knees, but up here they’ll sit on it and hit it 350 feet. I knew that I needed to make it harder, with more of a cutter-ish shape, so I approached Carson.”

Cross had thrown an effective slider at the University of Connecticut and later at the lower levels of the St. Louis Cardinals system. Moreover, he’d recently developed a strong interest in pitch design. He was just the tutor Tabor needed.

“I basically taught Matt how to throw a bullet slider,” explained Cross, whom the Brewers recently appointed as the pitching coach for their low-A affiliate, the Wisconsin Timber Rattlers. “He needed something that bites in the other direction from his fastball and changeup, and through a trial-and-error process we found that he could replicate that one the easiest. ”

Not surprisingly, technology played a key role.

“A big thing was the slow-motion video camera, the Edgertronic,” explained Tabor. “Those are super cool. Instead of just being able to say ‘I felt this,’ after throwing a pitch, it’s ‘I felt this, and this is exactly what happened.’ Carson was behind me, taking every single clip, and we would go over them together. He’d say, ‘Here is where you should be putting more pressure on this finger, and taking pressure off this finger.’ He was basically a coach on the mound with me. It was other little nuances too, like maybe tilting the ball five degrees forward, or back, to try to get the spin axis where we wanted it.”

According to Cross, a bullet slider spins gyroscopically, making the pitch difficult to pick up. In his words, “Hitters can’t really see the laces like they do on a true slider, which creates the dot.” The movement is almost entirely vertical. Paired with the decrease in velocity from a fastball, the pitch plays not unlike a changeup. The finger pressure Tabor mentioned factors into the movement profile.

“A good bullet slider is going to come from a lot of index-finger pressure,” said Cross. “When you’re creating a curveball, or a slurvy pitch, there’s going to be that proprioception off the middle finger. Getting more involved with the index finger is when you create that bullet profile. A cue we’d use is that when you’re getting close to release, you think about driving your index finger into the ball rather than thinking about manipulating the ball.”

Tabor has taken manipulation out of his slider mindset.

“I throw the crap out of it, which is why it’s 85-87 [mph],” the youngster told me. “That way it’s the down-slider I want. My thumb is the side of the baseball, and I tilt my hand like… you know how you pronate on a changeup? I kind of preset my wrist in that kind of handgun, side-of-the-ball position. Then I throw it as hard as I can.”

The velocity matters. Based on what Cross has learned from analytical studies, a bullet slider is typically most effective at 85 mph and higher.

Tabor used to have his thumb more on the bottom of the baseball. He moved it up on Cross’s suggestion, and the new placement helped create bullet-spin action, rather than the slurvier side-to-side he’d had previously. Along the way, Cross convinced Tabor to trust the process. That meant focusing on what he could control and not the end results of individual throws.

“We had the high-speed camera, and we’d watch that first 10 feet out of the hand,” Cross explained. “We needed to see if we were consistently creating the spin we wanted. Once we created that spin, we would basically trust that the ball would move the way we wanted it to, rather than be preoccupied with how the ball was moving close to home plate.”

A second New England-area pitching professional played a meaningful role in Tabor’s slider development. Kevin McGowan, who made a handful of relief appearances for the New York Mets in 2017, had also been working out at PowerHouse Sports.

“I don’t know if he realizes it, but Kevin McGowan really helped me with it,” said Tabor. “He was there one day and showed me the grip that the Mets kind of use — that power cutter, downer slider, grip. He was talking about his experiences with Jacob deGrom and Noah Syndergaard, and the way they developed, and throw, theirs. The biggest turning point for me probably came that day.”

And then there are Mike Parrott — Tabor’s pitching coach in Kane County — and (albeit indiectly) Tom Brady.

“Bird has obviously worked with me on my slider,” Tabor said of Parrott. “He was a real help last year. And another big thing I’ve done is start throwing a football every single day. That’s helped my slider exponentially. In order to throw a football, to throw a spiral, you have to get on the side of it and feel it run off those two fingers. For me, that’s the same feel as a slider. I kind of had to prove my case with [the Diamondbacks] on why I wanted to throw a football every day, but God bless them, they embraced letting me do it.”

Cross gets props for that suggestion as well.

“I think it was Carson’s idea,” Tabor told me. “I was a quarterback in high school, so it’s kind of something I’ve done for a long time. Up in PowerHouse is where I really started doing it, and I wasn’t throwing a football just for fun, I was throwing it for a purpose.”

Ever purposeful, he continues to grow and evolve on the mound. While his fastball velocity remains 90-94, Tabor has begun experimenting with a curveball at the suggestion of Arizona minor-league pitching analyst Ross Seaton. Moreover, the slider he learned from Cross has undergone an evolution of its own.

“It probably moves about six inches, but the action is more like three-to-nine [on a clock] now,” said Tabor. [Another of Arizona’s pitching analysts shared that the organization wanted at least some sweep.] “It’s kind of in between a cutter and a downer slider. It’s somewhere in the middle, but without the recognizable spin. It still has that bullet spin I learned from Carson at PowerHouse.

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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4 years ago

Great stuff! Thanks!