Washington Nationals
Although they have not thrown an MLB pitch in 2025, Mason Thompson threw 1,778 pitches that were tracked by the PITCHf/x system between 2021 and 2023, including pitches thrown in the MLB Regular Season and Spring Training. In 2023, they relied primarily on their Sinker (95mph) and Slider (85mph), also mixing in a Curve (81mph) and Fourseam Fastball (95mph). He also rarely threw a Change (86mph).
In 2023, compared to other RHP:
Their sinker has an obvious tail, has well above average velo, results in somewhat more flyballs compared to other pitchers' sinkers and has some natural sinking action. Their slider is a real worm killer that generates an extreme number of groundballs compared to other pitchers' sliders and has some two-plane movement. Their curve generates more whiffs/swing compared to other pitchers' curves, has a sharp downward bite, is slightly harder than usual, results in somewhat more flyballs compared to other pitchers' curves and has slight glove-side movement. Their fourseam fastball generates an extremely high number of swings & misses compared to other pitchers' fourseamers, has some natural sinking action, results in somewhat more flyballs compared to other pitchers' fourseamers and has slightly above average velo. Their change (take this with a grain of salt because they've only thrown 2 of them in 2023) is basically never swung at and missed compared to other pitchers' changeups, has an obvious armside fade, results in more flyballs compared to other pitchers' changeups, is slightly firmer than usual and has some natural sink to it.