Gyroball? Bullet Slider? Garrett Whitlock’s New Pitch On Display

Red Sox pitcher Garrett Whitlock has added a new pitch to his arsenal. It's a gyro ball. Or is it a bullet slider? Maybe a gyro slider?

Whatever you want to call it, Whitlock under the watchful eye of new pitching coach Andrew Bailey, has augmented his pitch mix to include the new offering in an attempt to really stick as a starting pitcher. The early returns? Quite encouraging. Whitlock went five strong innings Sunday, allowing just one run on three hits while striking out eight in Boston's win over the Seattle Mariners.

The win not only secured a split for the Red Sox, but it continued an undeniable trend from the Boston pitching staff that should have fans excited about an ongoing overhaul of the organization's pitching philosophy under Bailey and chief baseball officer Craig Breslow.

For Whitlock specifically, he debuted the new pitch -- we'll call it the bullet slider for consistency's sake -- during spring training.

"It's a slider, but I don't throw it like a slider," Whitlock explained to The Boston Globe during spring training. "It's an off-speed pitch even though I throw it more like a fastball."

The mysterious pitch is, well, kind of confusing to completely understand, at least for those of us with an elementary-school understanding of physics. Fangraphs wrote about it in 2020, with then-Diamondbacks prospect Matt Tabor -- a Massachusetts kid, coincidentally -- who learned the pitch from Carson Cross at PowerHouse Sports New Hampshire. The pitch, according to the FanGraphs piece, spins "gyroscopically," which is certainly a word.

Sliders typically spin tightly in a direction that creates the illusion of a dot on the ball as it approaches the plate. The best hitters in the world have the eyes that can pick that up. This pitch doesn't because of the gyroscopic-ness of it all, instead spinning like a, you guessed it, bullet.

"Hitters can't really see the laces like they do on a true slider, which creates the dot," Cross explained to Fangraphs.

The pitch, which thrives on pressure from the index finger as opposed to the middle finger, has more vertical movement than horizontal movement. If there is horizontal movement, it's glove-side, which is helpful for a pitcher like Whitlock who has typically thrived on arm-side movement with his two best pitches: the sinker and changeup.

There's only one game of evidence so far, making it difficult to know for sure how often Whitlock used the bullet slider. Based on BaseballSavant's pitch tracking data, though, Whitlock threw a "slider" 16% of the time Sunday; last season, according to the same data, he threw exactly one "slider." So, that seems like it's the one.

According to the numbers, Whitlock threw it 15 times Sunday, generating a 25% whiff rate. The pitch averaged 44 inches of vertical break (or drop), and it hardly moved side-to-side, seemingly differentiating it from his sweeper. Of the eight swings the Mariners put on the bullet slider, only one was actually put in play, despite generating swings on 86% of the pitches in the zone. Seattle also chased the pitch, swinging half the time when one was outside the zone.

MLB registered this pitch, to strike out J.P. Crawford in the bottom of the first inning.

Whitlock leaned on the breaking stuff and changeup early in the outing, keeping in line with the rest of the staff so far, but he and catcher Reese McGuire "flipped the script," as manager Alex Cora said. Later in the outing, Whitlock turned to the sinker with Seattle looking for the soft stuff.

Ultimately, disrupting timing in (and around) the strike zone is what it's all about. The bullet slider doesn't need to become Whitlock's best pitch, but the Red Sox should hope it's the key to helping him unlock his potential as a starter they clearly see in the 27-year-old.