Arizona Diamondbacks
Merrill Kelly has thrown 14,458 pitches that have been tracked by the PITCHf/x system between 2019 and 2025, including pitches thrown in the MLB Regular Season, the MLB Postseason, The World Baseball Classic and Spring Training. In 2025, they have relied primarily on their Fourseam Fastball (92mph) and Change (88mph), also mixing in a Sinker (93mph), Slider (87mph), Cutter (91mph) and Curve (82mph).
In 2025, compared to other RHP:
Their fourseam fastball generates more whiffs/swing compared to other pitchers' fourseamers, has some natural sinking action, has essentially average velo and results in somewhat more flyballs compared to other pitchers' fourseamers. Their change dives down out of the zone, is much firmer than usual, results in somewhat more groundballs compared to other pitchers' changeups and has slight armside fade. Their sinker is basically never swung at and missed compared to other pitchers' sinkers, results in somewhat more groundballs compared to other pitchers' sinkers, has slight armside run and has some natural sinking action. Their slider results in more flyballs compared to other pitchers' sliders and has primarily 12-6 movement. Their cutter is an extreme flyball pitch compared to other pitchers' cutters, has surprisingly little cutting action, has well above average velo and has good "rise". Their curve is basically never swung at and missed compared to other pitchers' curves, is much harder than usual, has a sharp downward bite and results in somewhat more flyballs compared to other pitchers' curves.