Mitch Keller has thrown 927 pitches that have been tracked by the PITCHf/x system between 2017 and 2020, including pitches thrown in the MLB Regular Season and Fall/Winter Ball. In 2020, he has relied primarily on his Fourseam Fastball (93mph), also mixing in a Curve (77mph) and Slider (86mph). He also rarely throws a Change (88mph).
Basic description of 2020 pitches compared to other RHP:
His fourseam fastball generates fewer whiffs/swing compared to other pitchers' fourseamers, has essentially average velo and has slightly less natural movement than typical. His slider is an extreme flyball pitch compared to other pitchers' sliders and has less than expected depth. His curve has an exceptional bite, is basically never swung at and missed compared to other pitchers' curves and results in more flyballs compared to other pitchers' curves. His change (take this with a grain of salt because he's only thrown 6 of them in 2020) is basically never swung at and missed compared to other pitchers' changeups, is much firmer than usual and results in more flyballs compared to other pitchers' changeups.