Although he has not thrown an MLB pitch in 2020, Mitch Keller threw 791 pitches that were tracked by the PITCHf/x system between 2017 and 2019, including pitches thrown in the MLB Regular Season and Fall/Winter Ball. In 2019, he relied primarily on his Fourseam Fastball (96mph) and Slider (88mph), also mixing in a Curve (81mph). He also rarely threw a Change (91mph).
Basic description of 2019 pitches compared to other RHP:
His fourseam fastball has well above average velo and has slightly less natural movement than typical. His slider generates a high number of swings & misses compared to other pitchers' sliders, results in many more groundballs compared to other pitchers' sliders, is much harder than usual and has some two-plane movement. His curve is a real worm killer that generates an extreme number of groundballs compared to other pitchers' curves, has a sharp downward bite and is slightly harder than usual. His change is thrown extremely hard and is basically never swung at and missed compared to other pitchers' changeups.