Boston Red Sox
Kyle Harrison has thrown 5,492 pitches that have been tracked by the PITCHf/x system between 2023 and 2025, including pitches thrown in the MLB Regular Season and Spring Training. In 2025, they have relied primarily on their Fourseam Fastball (94mph) and Curve (82mph), also mixing in a Change (86mph) and Slider (88mph). He also rarely throws a Sinker (94mph).
In 2025, compared to other LHP:
Their fourseam fastball generates an extremely high number of swings & misses compared to other pitchers' fourseamers, has heavy sinking action, has well above average velo, results in somewhat more flyballs compared to other pitchers' fourseamers and has slight armside run. Their curve is thrown extremely hard, has little depth, results in somewhat more flyballs compared to other pitchers' curves and has slight glove-side movement. Their change dives down out of the zone, is much firmer than usual and results in many more groundballs compared to other pitchers' changeups. Their slider is thrown extremely hard, generates fewer whiffs/swing compared to other pitchers' sliders, has less than expected depth, has primarily 12-6 movement and results in somewhat more flyballs compared to other pitchers' sliders. Their sinker (take this with a grain of salt because they've only thrown 17 of them in 2025) generates a high number of swings & misses compared to other pitchers' sinkers, is an extreme flyball pitch compared to other pitchers' sinkers, has well above average velo and has some natural sinking action.