George Kirby’s Elite Command Can’t Mask a Growing Concern for the Mariners

Kirby hasn’t lost the zone. He may have become trapped inside it.

Aug 14, 2026; Houston, Texas, USA; Seattle Mariners starting pitcher George Kirby (68) pitches against the Houston Astros in the first inning at Daikin Park. Mandatory Credit: Thomas Shea-Imagn Images | IMAGN IMAGES via Reuters Connect

George Kirby is not struggling to throw strikes. The strikes are simply just getting hit. It’s been a growing problem for the Mariners. Kirby still owns a strong 5.6 percent walk rate, but his ability to dominate an at-bat after filling the zone continues to fade. 

Opponents are batting .285 against Kirby, the highest average allowed by any qualified pitcher in baseball. That’s a jarring place for a pitcher whose reputation was built around precision. What seems to be the growing problem is that hitters know he’s going to fill the zone. Meaning it’s up to Kirby and company to make sure the pitching plan prioritizes more deception. He'll look to see if he can change the course on Aug. 25 when he takes the mound against the Phillies.

George Kirby Is Winning the Strike Zone but Losing At-Bats

His strikeout rate has plunged from 26.1 percent in 2025 to 19.9 percent this season. His 21.6 percent whiff rate sits below the 25 percent league average. When hitters swing at Kirby’s pitches inside the strike zone, they make contact 86.9 percent of the time. That last number cuts directly to the problem. Kirby is winning the map and losing the fight.

Elite command is supposed to make good stuff more dangerous. Kirby’s command once worked that way. Now, it’s placing hittable pitches inside the zone with alarming consistency.

There is some bad luck at play. Kirby’s .260 xBA (Expected Batting Average) is noticeably lower than the .285 average opponents have produced, while his .309 xwOBA (Expected Weighted On-Base Average) is better than his actual .337 mark. His 4.00 xERA also sits below his 4.18 ERA.

We can blame a few extra hits on poor fortune. But it all points to a disappearance of dominance. Something that should concern the Mariners because Kirby was never supposed to survive as a contact-dependent starting pitcher. His calling card was the combination of premium velocity, pinpoint control and swing-and-miss.

Kirby hasn’t been overpowering his opposition. He’s challenging them, and he’s losing. 

That brings us to the uncomfortable topic surrounding the Mariners’ offseason plan. Kirby’s name still carries value because of his age, track record and remaining club control. His current performance carries much less. The Mariners would be trying to market a frontline starter while other teams point to the declining numbers and may see him as a rebound project instead of a pitching upgrade.

That gap could make Kirby extraordinarily difficult to trade for the impact return Seattle would expect. Teams will want him. They just won’t value him like the impact arm he once was.