Kansas City Royals
Stephen Kolek has thrown 4,406 pitches that have been tracked by the PITCHf/x system between 2023 and 2025, including pitches thrown in the MLB Regular Season, The World Baseball Classic, Spring Training and Fall/Winter Ball. In 2025, they have relied primarily on their Sinker (94mph), Fourseam Fastball (94mph) and Slider (84mph), also mixing in a Cutter (91mph) and Change (87mph). He also rarely throws a Curve (80mph).
In 2025, compared to other RHP:
Their sinker has heavy sinking action, results in somewhat more groundballs compared to other pitchers' sinkers, has slight armside run and has slightly above average velo. Their fourseam fastball has heavy sinking action, has essentially average velo and results in somewhat more groundballs compared to other pitchers' fourseamers. Their slider generates fewer whiffs/swing compared to other pitchers' sliders, has short glove-side cut and has some two-plane movement. Their cutter has slightly above average velo and has some natural sink. Their change is a real worm killer that generates an extreme number of groundballs compared to other pitchers' changeups, dives down out of the zone and is much firmer than usual. Their curve (take this with a grain of salt because they've only thrown 2 of them in 2025) is basically never swung at and missed compared to other pitchers' curves, results in more flyballs compared to other pitchers' curves, has a sharp downward bite and is slightly harder than usual.