Seattle Mariners' George Kirby Draws Spotlight Because of Potential New Pitch Weapon
In this story:
There's times where the Seattle Mariners starting rotation better resembles a laboratory run by mad scientists rather than a pitching staff.
Despite being arguably the best starting rotation in baseball, the staff isn't content with resting on its laurels. Dating from the middle of last season to now, every starter - and All-Star closer Andres Munoz have all made adjustments to their current repertoire's or have worked on a new offering.
Seattle starting pitcher George Kirby pitched in his first spring training game of the season against the Athletics on Wednesday. He didn't have the cleanest outing. He threw one inning and struck out one batter, allowed one earned run and walked two hitters. The biggest takeaway from Kirby's start was a new cutter.
George Kirby's New Cutter. pic.twitter.com/9NugusXWu5
— Rob Friedman (@PitchingNinja) February 26, 2025
Kirby threw the cutter just 11 times out of 2,967 total pitches in 2024, according to Baseball Savant.
Kirby is already one of the best command pitchers in the game. But a recent story highlighted how introducing a cutter could benefit him.
An article written by The Athletic's Eno Sarris mentioned how Kirby's thrown his four-seam fastball with two strikes a third of the time in his career. This works out well often for Kirby. But Sarris also pointed out how in August of last season, hitters slugged .857 against the four-seamer with two-strikes.
Sarris also pointed out how left-handed batters have done well against the fastball compared to righties.
Kirby's cutter could be the solution to getting out lefties at a more efficient rate. In the 11-pitch sample size in 2024, his cutter was often located on the inside of the plate for left-handed pitchers. In the nine segmented areas inside the strike zone, Kirby generated the second-lowest to fourth-lowest exit velocities in the areas the cutter was located the most (also according to Baseball Savant).
It's not that Kirby needs help, necessarily. Of the pitches that Kirby threw at least 100 times in 2024, hitters maxed out at a .253 average against his sinker. Hitters averaged .226 against his slider and .230 against his four-seam fastball.
George Kirby, Painted 96mph Sinker. 🖌️🎨 pic.twitter.com/PntblhjTCV
— Rob Friedman (@PitchingNinja) May 14, 2024
Adding a cutter to the mix could help Kirby avoid bad stretches or the rare demerit on what is an otherwise stellar ledger.
Related Stories on Seattle Mariners
MARINERS OUTFIELDER MITCH HANIGER DISCUSSES SPRING TRAINING GOALS: Haniger entered this offseason in a different place than a year ago and is hoping to rebound after a disappointing 2024. CLICK HERE
SEVERAL MARINERS AMONG HARDEST HITTERS IN SPRING TRAINING: For the second time in three days, multiple Mariners hitters had some of the highest recorded exit velocities in baseball. Ben Williamson and Julio Rodriguez helped the M's to a win over the Los Angeles Dodgers. CLICK HERE
MARINERS SLUGGER LUKE RALEY SCRATCHED FROM GAME DUE TO BIRTH OF HIS CHILD: The Mariners infielder was slated to play Feb. 25 against the Los Angeles Dodgers but was scratched after his wife went into labor. CLICK HERE
Follow Seattle Mariners on SI on social media
Continue to follow our Inside the Mariners coverage on social media by liking us on Facebook and by following Teren Kowatsch and Brady Farkas on "X" @Teren_Kowatsch and @wdevradiobrady. You can subscribe to the "Refuse to Lose" podcast by clicking HERE.
