How Ryan Pepiot’s Fastball Is Driving an Imminent Breakout

This one simple fastball trick made him an ace! Batters hate him!

In the modern landscape of Major League Baseball, one of the most common archetypes for a young pitcher is that of the “great stuff, questionable command” variety. Teams have placed such a strong emphasis on pitch movement and velocity that guys like Joe Boyle are getting consistent cracks at making a starting rotation despite barely being able to throw two consecutive strikes.

The Los Angeles Dodgers have housed a seemingly endless supply of these arms over the last few seasons. Gavin StoneLandon KnackBobby MillerEmmet Sheehan, and Michael Grove have each factored into their starting rotation in just the last two years, with more on the way in Kyle Hurt and River Ryan among others.

Another product of the Dodgers’ player development machine in this timeframe was 2019 third-rounder Ryan Pepiot, who found himself moving across the country after being traded to the Tampa Bay Rays as part of the December 2023 Tyler Glasnow deal. Similar to his young Dodgers contemporaries, Pepiot was packing a formidable arsenal with plenty of raw arm talent, but there were lingering doubts about his ability to command that arsenal effectively enough to lock down a rotation spot.

He was given a 40 present, 45 future command grade upon graduation, and the consensus on him was that a career as a reliever was among the potential outcomes for the then 25-year-old. Fast-forward to 2024, and Pepiot is currently the best-performing starter in a perpetually deep Rays pitching corps, sporting a resplendent 0.87 WHIP and 21.5 K-BB% through six starts.

What gives? How is a guy with fringy command who did nothing to quell concerns with a 16.9% walk rate in his first taste of big league action suddenly maintaining a better-than-average walk rate and suppressing baserunners better than almost anyone in the league?

Let’s do some digging into Pepiot and what changes he’s made between Los Angeles and Tampa Bay.


A New Best Pitch


Coming up as a prospect, Pepiot was notable for having one of the very best changeups in Minor League Baseball. The pitch was given a 60/60 grade by evaluators, was returning whiff rates in the 30’s, and served as the primary driving force behind his excellent MiLB strikeout rates. He leaned heavily on it in his 2022 and 2023 stints in Los Angeles, tossing it 25.6% and 34.7% of the time, respectively. And why wouldn’t he? When you have a changeup with 16 inches of arm-side fade at 86 MPH, you use the thing.



As Pepiot threw the pitch more, however, it’s effectiveness started to waver for the first time as a professional. Hitters slugged .510 against the changeup in his 28 September and October 2023 innings compared to just .150 in August, and he started avoiding the zone with it in response. His fastball and slider were good enough offerings to buoy his performance, but the end of 2023 indicated that Pepiot would probably have to beef up his arsenal somehow if he was going to sustain success over a full Major League season.

Enter 2024, and Pepiot is now getting a fresh start with one of the only other organizations in the league that can match the Dodgers’ pitching development prowess down in Tampa Bay. The assumption coming into the season was that the changeup would once again serve as Pepiot’s leading putaway pitch, but things haven’t played out that way 34 innings into the young season. Not only has the changeup arguably been his worst pitch to this point in the season, but he’s actually demoted it to his third most frequently-used offering.

Intuitively, you would think this is a bad sign. The pitch that did a lot of the heavy lifting getting a pitcher to the Major Leagues and drove much of his early success suddenly becomes a tertiary offering with middling results. That sounds like a recipe for regression. Turns out, this may have actually been by design. The rest of Pepiot’s arsenal has noticeably improved in his first season with the Rays, most notably his four-seam fastball.


Ryan Pepiot Four-Seam Fastball ’23 vs. ’24

Sometimes it can be tough to identify exactly why a pitch gets so much better in just one season, but not in Pepiot’s case. His new and improved four-seamer is the result of two main factors: ride and location.

Pepiot had a good fastball characteristically before joining the Rays, but it’s reached a new level in 2024. He’s added an inch and a half of induced vertical break and ever-so-slightly dropped his release point to create a much flatter approach. His 1.3 height-adjusted VAA (the vertical angle at which a pitch approaches home plate) ranks in the 84th percentile among MLB starters.

That’s a great change and a significant one for Pepiot’s purposes. Creating a flatter fastball only gets you so far, though. Four-seamers with high VAAs play far better at the top of the strike zone where they can generate whiffs, so Pepiot would need to start elevating the fastball to fully capitalize on his improved movement profile.

And elevate he did! His hiLoc% (percentage of pitches thrown in the upper third of the zone or above) increased from 44.4% last year to 50.2% this year. It’s not a drastic increase and that new figure only puts him in the 48th percentile among starters, but there’s no doubt that his intent to elevate has made a huge difference in his fastball performance.

The changes to Pepiot’s fastball movement and intent have made it a lethal weapon in the strike zone. Batters are only making contact against it 70.1% of the time, which is the best mark among all qualified starting pitchers.



With how dominant this pitch has been when located up in the zone, it’s no wonder he’s been so confident with it. That is sort of the Rays’ mantra for pitchers: throw your best pitch in the zone early and often, and the rest will take care of itself. The interesting part is that the fastball wasn’t seen as Pepiot’s best pitch coming into Tampa Bay, but they treated it like it was from the very beginning.

In acquiring Pepiot, the Rays likely identified that the four-seamer had untapped potential that could be brought forward with some adjustments to intent and location. With just those changes, it has become one of the more effective offerings thrown by a starter so far this season.

There’s no doubt that the four-seamer has been responsible for a large portion of Pepiot’s early-season success, but what could really take him to the next level is how the rest of his arsenal is shaped around it.


Re-Designing The Secondaries


What really gets me excited about Pepiot is the fact that his results have been great so far even without much help from his changeup. Just watching him, you can tell he isn’t totally comfortable with his command of it yet. The mLoc% (percentage of pitches located in the middle horizontal band of the plate) on his changeup has increased from 16.7% in 2023 to 26.0% this year, suggesting he’s having a harder time keeping it down and out of the heart of the zone.

That would explain why hitters have seen a 70-point increase in wOBA against the pitch this year and why its whiff rate has dropped by almost 11%. That said, I wouldn’t expect the struggles with changeup command to continue to this extent. Unless Pepiot somehow totally lost his feel for the pitch, it’s something that will likely come and go from time to time.

Nothing much has changed with the changeup intrinsically. The only somewhat notable difference in its movement profile is that it is dropping slightly under an inch less than it was last year. That could very well be a result of Pepiot’s increased emphasis on fastball ride bleeding over into his other pitches (his slider has also gained about half an inch of carry), but the velocity, arm-side movement, and approach angles all remain intact.

Pepiot’s slider has been similar to its 2023 iteration in terms of results, but there has been a very slight adjustment to its movement profile that I think warrants discussion. This year, the slider has gained about a half-inch of ride and a half-inch of horizontal break at the same velocity.

One thing I’ve noticed about the Rays is that they like giving guys breaking pitches with a good amount of carry to them as opposed to more depth-y secondaries with a ton of vertical drop. Zack Littell’s slider gained over an inch of ride and more closely resembled a traditional cutter when he moved to Tampa Bay in 2023, and the pitch improved immediately upon arrival.

In Pepiot’s case, his altered slider now has almost 6 more inches of carry than the average one thrown by right-handed starters in 2024 while also featuring above-average arm-side movement. If that wasn’t enough, it is also thrown 3 MPH harder than average as well. This combination of factors gives his slider one of the highest adjusted vertical approach angles among all starters.


Ryan Pepiot SL vs. Average Among RH SP (min. 10 Pitches)


This altered slider likely interacts very well with Pepiot’s improved four-seamer, giving batters a breaking pitch with more ride that can be leveraged particularly well against lefties.

With the change in movement profile has come a pretty significant shift in locations for Pepiot’s slider. That higher VAA allows the pitch to play well up in the zone, and Pepiot clearly recognizes this. The hiLoc% on it has gone from 24% in 2023 to 33.6% this year, ranking in the 93rd percentile among starters.

This change in intent has been accompanied by an improved whiff rate and a spike in usage against lefties. In 2023, Pepiot only threw the slider 4% of the time against left-handed batters and did not record a single whiff. This year, he’s throwing it 25% of the time against them and is maintaining a 13.6% swinging-strike rate.

Looking into his splits also reveals some interesting insight into his slider shape. Against righties, Pepiot’s slider is at a dead even 7″/7″ in vertical/horizontal movement at 88.4 MPH. Against lefties, however, it has over an inch more carry, less glove-side break, and is being thrown slightly harder. This cutter-ish shape against left-handed hitters has allowed him to rack up whiffs at the top of the zone, prompting batters to swing under it.



This is a really exciting interaction between Pepiot’s fastball and slider that I think gives him many more attack patterns when facing tough left-handed hitters. The increased ride on his fastball paired with his new adaptable slider and ever-present changeup makes this an incredibly well-rounded core arsenal that I think can sustain Pepiot against lineups two or three times over in any given start.

The pieces were all there coming into Tampa Bay, and the Rays have done well to round out his repertoire and mold him into a more dynamic starting pitcher.


What’s Next?


We could spend all day diving into the minutia of Pepiot’s new arsenal and discussing how these changes play better in certain matchups, but the bottom line is this: turning Pepiot’s four-seam fastball into one of the best pitches thrown by a starter this season has unlocked an entirely new level for him.

His mix, which originally orbited around his changeup, is now littered with great options against hitters on both sides of the plate and is infinitely more flexible on a start-to-start basis. We haven’t even discussed the fact that he just casually added a curveball with almost 11 inches of drop and a true cutter with 14 inches of ride at 92.3 MPH because, quite honestly, he hasn’t needed them to this point in the season.

Pepiot has effectively put to rest many of the concerns surrounding his command by giving himself two extremely reliable strike-throwing options that he has shown an ability to elevate for whiffs or leverage for soft contact.

Still, the most exciting thing about him is that he may not be done evolving. Those two pitches I mentioned earlier, the cutter and curveball, have great promise to play more central roles in his arsenal. I think once the league has a more thorough scouting report on the 2024 version of Pepiot, the next step will be for him to incorporate those pitches more to give hitters looks at five distinct offerings.

In particular, if he can learn to land that big curveball for strikes in the zone and command that cutter to both sides of the plate, I think he’ll be nigh unstoppable. Neither of those is particularly easy to accomplish, but Pepiot has already shown a propensity to surprise us with how quickly he can adapt to a new approach and deploy it against major league lineups.

The raw arm talent, stuff, and adaptability are all there for Pepiot to vault himself into the upper echelon of starting pitchers in the league. It was tough to imagine this scenario coming to pass so quickly after being acquired by the Rays, but my outlook on him has changed rapidly from just another intriguing arm with a limited arsenal and fringy command to a burgeoning ace with a fully realized set of weapons at his disposal.

At the end of the day, giving Pepiot a fastball that he can confidently throw in the zone whenever he wants to has unearthed a world of possibilities for him, and I can’t wait to see in what direction he decides to take this.


Photos by Dustin Bradford/Icon Sportswire and Andrew Ridley/Unsplash | Featured Image by Ethan Kaplan (@DJFreddie10 on Twitter and @EthanMKaplanImages on Instagram)

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