FINAL GRADES: George Kirby's Command Helped Elevate Seattle Mariners Rotation
The Seattle Mariners were expected to have one of the better starting rotations in the league heading into 2024 and they somehow managed to exceed those expectations.
And a large part of that success was 2023 All-Star George Kirby.
Kirby has been the pinnacle of consistency since his debut in 2022. And that trend continued in 2024.
Kirby boasts arguably the best command out of the Mariners entire starting rotation. An impressive feat considering the experience of Luis Castillo and the arsenal of Logan Gilbert and Bryce Miller.
Although Seattle's 2024 All-Star ended up being Gilbert, there was an argument to be had, especially at the All-Star break, that Kirby could have earned a trip to the Midsummer Classic, too.
After all, Kirby had one of the most impressive streaks in the league.
George Kirby by the numbers
Games started: 33
Pitching stats: 3.53 ERA, 33 appearances (33 starts), 14-11 record, 191.0 innings pitched, 179 strikeouts, 1.07 WHIP, 20 QS, .245 opp. BA, 4.2 WAR
Advanced pitching stats: 3.39 xERA, .238 xBA, 31.9% chase, 23.9% whiff, 3.26 FIP, 8.43 K/9, 71.6% LOB
What I liked
I mentioned Kirby's command earlier, and that's without a doubt his strength. You probably don't have to use more than two hands to count the number of starters in the league with better location than Kirby. And that's being generous.
And Kirby had a lot of different throws in which he displayed that.
Kirby has an arsenal of seven pitches, according to Baseball Savant: A four-seamer, a slider, a sinker, a splitter, a knuckle curve, a cutter and a straight knuckle ball. He used his fastball, slider, sinker and splitter at least 10% of the time. He used his heater, slider and sinker over 20%.
Kirby also struck up a relationship with backup catcher Mitch Garver. Those two were often the pitcher-catcher combo during most of Kirby's starts in the second half of the season. That allowed starting catcher (and likely Gold Glove/Silver Slugger award winner) Cal Raleigh to get some much-deserved rest.
Kirby had a streak of nine consecutive quality starts from June 9-July 26, the highest consecutive streak of that stat in the entire league.
Kirby's effectiveness did start to dip in the second half of the year starting with an outing against the Boston Red Sox on July 31. But he managed to close out the year strong with three straight quality starts.
Best game
Kirby had three starts of seven innings pitched while allowing no runs. His first of such appearances was undoubtedly his best.
On April 27 against the Arizona Diamondbacks, Kirby threw seven innings and struck out 12 batters without giving up a run. He walked one batter and let up two hits.
George Kirby's 11th and 12th Ks. 😯 pic.twitter.com/knfxRCIxOw
— Rob Friedman (@PitchingNinja) April 28, 2024
Considering this is the same Diamondbacks team that led the league in runs scored in 2024, there may not be a better game to point to as to what Kirby is capable of doing at his best.
Future prospects
George Kirby this year set a new career high in starts (33), innings pitched (191) and strikeouts (179).
Outside of that, Kirby's stats have fluctuated very little in his three pro years. Almost painfully so.
His single-season ERA over his career has been 3.39, 3.35 and 3.53. His K/9 over the same stretch has been 9.21, 8.13 and 8.43.
That's not to say that there still isn't room for Kirby to improve. His second-half showed that. Despite closing out the year with three consecutive quality starts, he still had a 4.08 ERA in his last seven appearances.
Kirby has been a consistent mid-3.00 ERA pitcher. And even though he doesn't have as much potential as teammates Bryan Woo or even Gilbert, there's still room for Kirby to be a sub-3.00 pitcher in 2025.
Final Grade: B
B: The second half of the year is what brings Kirby down in the final grade. It wasn't bad. But his first half was so elite that it was hard to not take the drop-off into consideration when giving out the final assessment,
Kirby and Gilbert are the glue of the rotation. Castillo is the veteran from outside the Seattle farm system and Woo and Miller will be in their third seasons in 2025. If even one of those two falter, the rotation isn't nearly as effective.
Kirby is an "A" pitcher. He'd be the ace on a handful of rosters across the league.
There's no reason to assume that Kirby's will have a drop-off in the second half in 2025 to the extent he did in 2024.
And if the Elon College product can keep up his elite play across a whole season, then his status as an "A" pitcher will just be reaffirmed.
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