Miami Marlins
William Kempner has thrown 774 pitches that have been tracked by the PITCHf/x system between 2024 and 2026, including pitches thrown in the MLB Regular Season, Spring Training and Fall/Winter Ball. In 2026, they have relied primarily on their Fourseam Fastball (96mph) and Slider (82mph), also mixing in a Cutter (88mph). He also rarely throws a Sinker (95mph), Splitter (86mph) and Change (87mph).
In 2026, compared to other RHP:
Their fourseam fastball generates an extremely high number of swings & misses compared to other pitchers' fourseamers, has heavy sinking action, has an obvious tail, results in more flyballs compared to other pitchers' fourseamers and has well above average velo. Their slider sweeps across the zone and results in more flyballs compared to other pitchers' sliders. Their cutter (take this with a grain of salt because they've only thrown 18 of them in 2026) has heavy sink, is basically never swung at and missed compared to other pitchers' cutters and is an extreme flyball pitch compared to other pitchers' cutters. Their sinker (take this with a grain of salt because they've only thrown 15 of them in 2026) has heavy sinking action, has an obvious tail, results in more flyballs compared to other pitchers' sinkers and has well above average velo. Their splitter (take this with a grain of salt because they've only thrown 7 of them in 2026) has dives down out of the zone, generates an extremely high number of swings & misses compared to other pitchers' splitters, is an extreme flyball pitch compared to other pitchers' splitters and is slightly firmer than usual. Their change (take this with a grain of salt because they've only thrown 2 of them in 2026) is basically never swung at and missed compared to other pitchers' changeups, dives down out of the zone, is much firmer than usual, results in more flyballs compared to other pitchers' changeups and has slight armside fade.