Bryan Woo Anchors Mariners' Rotation with Dominant, Deceptive Four-Seam Fastball

Bryan Woo has solidified his role as the Seattle Mariners' most dependable starter in 2025, largely due to his "superpower" four-seam fastball. Opponents are hitting a mere .152 against the pitch, the lowest mark among MLB starting pitchers, complemented by a 28.6% whiff rate. Woo's impeccable command and smooth delivery amplify the pitch's effectiveness, making it appear to rise to hitters, as noted by Mookie Betts. He recently set an MLB record with 25 consecutive starts of at least six innings and two or fewer walks, surpassing Juan Marichal. Drafted by the Mariners in 2021 after Tommy John surgery, Woo's potential was recognized despite a high college ERA. He learned to leverage his low release height for optimal fastball placement high in the zone and later added a two-seam fastball. His fastball variations comprise 73% of his pitches, the highest rate for any MLB starter. Teammates and coaches praise his deceptive stuff and bravery in the strike zone, with his 4% walk rate among the league's lowest.