Last season, one of the Mariners' young hurlers led the league in walk rate (0.9) and strikeout to walk rate (9.1) and made the American League All-Star team. The budding ace added a couple of extra ticks on his deadly four-seamer (up to 96 mph), unveiled Pitching Ninja's top knuckler of the year, and even started throwing a splitter to neutralize lefthanders. George Kirby, had a phenomenal 2023 season, and apparently, the folks at Major League Baseball think he has even more in the tank.
While it's great to see Kirby and the Mariners receiving positive press this offseason, the 25-year-old righthander has graduated from sleeper status. Take a peek at his Baseball Savant page; he's in the 90th percentile in pitching, fastball run value, and walk rate. Kirby is in the 80th percentile in fastball velocity, chase rate, and breaking ball run value. The former first-round pick has such a dominant fastball (BAA .234) that he can pepper the strike zone with it. Kirby's ceiling is probably the number one on this staff, and the stats back it up.
MLB insider, Luke Arkins recently compared Kirby's first two years to future MLB Hall of Famer, Zach Greinke‘s initial two seasons. The lanky Mariner hurler's performance is marketably better than Grienke's and it's not even close.
One thing to keep in mind is George Kirby received seven AL Cy Young votes, which shows that people, at least the media know about him. Let's hope Kirby's star continues to rise with another stellar season in 2024, but let's not label him a sleeper because he's graduated from that list.