Logan Gilbert's New Splinker, Paul Skenes New Two-Seamer, David Festa's New Sinker

A collaboration Post with Nick Pollack, Eno Sarris, and Eric Samulski

This post is part of a collaboration with Nick Pollack, Eno Sarris, and Eric Samulski. We each picked 3 pitchers with new pitches and dug in. Below are links to their pieces which I encourage you to read…

Nick Pollack (link) - Cristopher Sanchez, Jared Jones, Grayson Rodriguez

Eno Sarris (link) - Clay Holmes, Casey Mize, George Kirby

Eric Samulski (link) - Kevin Gausman, Griffin Canning, Kyle Harrison

Logan Gilbert: Splinker? Death Ball?!

Last year, Gilbert changed his stride direction to land more open and dropped his arm slot 8 degrees. The result was a full mph gain in four-seam velocity alongside a ~25% haircut in four-seam usage. He added a sweeper (tagged in Savant as a curveball) and a cutter with a bunch of lift. The latter was responsible for most of his four-seam usage drop to left-handed hitters. Those were a lot of adjustments. I thought he was done tinkering. I was incorrect.

We have a recent quote from Gilbert that he’s working on, “…a version of a sinker.” I assume that he’s talking about a splinker. It’s a recently coined pitch popularized by Jhoan Duran and Paul Skenes that combines a splitter's drop with a sinker's velocity. It’s achieved by lightly splitting your fingers on the ball, often with a two-seam orientation, instead of wedging the ball between said fingers like most splitters. The advantage is a pitch in the few iterations we’ve seen that can generate the ground-ball rate of a sinker and the swing-miss of a splitter.

I envision this pitch acting as a way for Gilbert to bust right-handed hitters inside. He didn’t have split issues last year, but he generated considerably more swing-miss versus left-handed hitters. If he intends to reconcile that difference, a new weapon to keep righties honest on the inner third of the plate that has velocity makes sense.

Gilbert threw 44 sinkers last year. The pitch had more lift than the average sinker for his slot, acting like a two-seam fastball. His potential “splinker” is presumably one to help him create more drop on the offering and maintain the velocity as much as possible.

Jhoan Duran’s “Splinker” Grip

But wait, there’s more! Buried underneath this potential splinker news is that Gilbert may also be adding a death ball. (I’ll defer to the folks at Tread Athletics for a detailed explanation.) Put simply, it’s a slider with more depth or a harder curveball. Bryce Miller’s 2023 curveball had standard shape: 79 mph, -14” induced vertical break (iVB), 8” glove-side movement. The death ball he debuted in 2024 was notably harder and shorter: 85 mph, -7” iVB, 2” glove-side. FanGraphs Stuff+ graded Miller’s 2024 death-ball curve as an average offering.

Gilbert’s utility, if he actually debuts this offering, is likely to make himself even more dominant versus left-handed hitters. He posted a 25% K-BB versus southpaws last year, where 13% is the league average. The curious thing is that Gilbert’s slider acts as his primary offering to lefties. At 88 mph with 0” iVB, it would draw pretty close in shape to a potential death ball, which I’d peg similar to Miller’s—85 mph, -6” iVB, 0” glove-side. In the modern age of pitch design, the bleeding of one pitch into another has become less common, but it’s still a consideration. We’ll see if Gilbert can execute not one, but two new offerings this year.

The Mariners can’t seem to help themselves with new pitches. Andres Munoz has both a new kick-changeup. Bryce Miller has a new cutter shape. George Kirby has a cutter now as well.

Paul Skenes: Two-Seam, Cutter

Skenes didn’t need more pitches. He had great results, minimal early-count fastball usage, and an underutilized offering in his changeup. But in the year of the pitch mix, anything goes. We have reports that Skenes is adding a running two-seam fastball and a cutter.

The two-seam fills a simple hole for Skenes—he doesn’t cover middle-in to up-in versus right-handed hitters. Skenes also pitches backward more than almost any other starting pitcher in MLB. He throws 49% four-seam with two strikes and just 34% four-seam in non-two-strike situations. That’s the 4th highest increase in four-seam usage into two-strike situations among starting pitchers (76-pitcher sample). If you’re Skenes, despite how good your fastball is, it still has the highest chance of getting barreled. Perhaps he’ll pull down his two-strike fastball usage, using more breaking balls in late-count situations. To set those pitches up, however much that matters for a pitcher with some of the weirdest right-handed angles in the sport, a two-seam to throw up and inside makes sense. Like everything else he throws, it’ll likely grade out above-average to plus. I’ll predict it sits 98 mph with 9” induced vertical break (iVB) and 17” arm-side movement. His four-seamer is 99 mph with 11” iVB and 14” arm-side movement. Given his natural bent for efficient fastballs, I don’t expect this to drop much. (That’s why he has the splinker.)

Paul Skenes’ locations to right-handed hitters. (The elevated “4S” red dot is his location in two-strike counts.)

The addition of a cutter for Skenes is more of a black box. The same “cover all quadrants” approach doesn’t work when thinking about Skenes versus left-handed hitters because he mostly does. His four-seam to lefties in non-two-strike counts is inside. If he trusts this cutter enough, more plate coverage would mean moving his four-seam to the outer third of the plate and leaving the cutter inside. He could also continue to throw four-seamers inside and place cutters inside off the four-seam. Or there’s a scenario where the “cutter” he’s describing turns out to be more of a gyro slider shape, think more drop than a traditional cutter. This would allow it to sit down-and-in for swing miss and fit snugly into the rest of his mix.

I don’t doubt Skenes and the Pirates have done their due diligence on the potential addition of the cutter. The fit in his mix is cloudier than the sinker at present. If anything, the addition of these pitches represents the continual shift away from four-seam fastballs in the sport. When you’re Paul Skenes sitting 99 mph, that says a lot about the quality of fastball needed to justify 45%+ usage.

David Festa: Sinker

Yesterday, I spoke with students from Vanderbilt’s Sports Business group. One student asked how far off I thought public pitcher analysis was from what teams do internally. Teams have biomechanic data and seam effect tools that we won’t come close to having on the public side (I hope I’m wrong). This limits our ability to consider how to implement a change with a pitcher. We’re somewhat blind—without on-field experience—to which seam orientations would elicit more glove-side movement for a cutter or how to reconcile the difference between a pitcher’s in-game velocity and his expected velocity based on his weight room stats.

I didn’t think the public’s ability to identify an issue with a pitcher, however, was considerably lower than what teams do internally. Are you a right-handed pitcher with a well-graded four-seam fastball? And does that pitch seem to play down against right-handed hitters? Then you should probably be throwing a sinker. We’ve seen this just this spring with Jared Jones, Griffin Canning, Max Meyer, Jack Leiter, and now David Festa.

I ranked Festa as my 12th-best pitching prospect in MLB late last season. I feel ok about that rank. He has some quirky body dynamics. He has three average-or-better pitches and now he’s addressing a clear issue from last season: his four-seam fastball versus right-handed hitters got beat up. Hitters barreled it on 17% of batted-ball events (11% is average). He generated below-average whiffs and his location was aggressive over the middle of the plate. The formula is to elevate the fastball more and let the sinker chew up the inner third of the plate.

Festa is a vertical pitcher with his four-seam and slider combination, a poor man’s Tyler Glansow. We saw the Twins take Louie Varland’s main breaking ball and split it into a pair of pitches last spring—a cutter and a short curveball. I can envision a scenario where a similar conversation came up internally with Festa, especially if you were worried about the effectiveness of his right-handed approach without a lateral breaking ball. At the moment, it doesn’t seem like a breaking ball split will happen. Perhaps Festa’s extension and mechanics make the bullet slider he throws play up relative to the raw specs. Or perhaps we look back in a year and see a new breaking ball.

For now, I will appreciate the addition of a sinker and hope his changeup performs better right-on-right in 2025. He may not have a rotation spot out of camp, but I think he and Zebby Matthews are better pitchers than Chris Paddack or Simeon Woods Richardson.