Although he has not thrown an MLB pitch in 2019, Dillon Peters threw 1,018 pitches that were tracked by the PITCHf/x system between 2017 and 2018, all of them occuring in the MLB Regular Season. In 2018, he relied primarily on his Fourseam Fastball (92mph) and Curve (77mph), also mixing in a Change (84mph). He also rarely threw a Slider (87mph).
Basic description of 2018 pitches compared to other LHP:
His fourseam fastball is straight as an arrow, has some natural sinking action and has essentially average velo. His curve has an exceptional bite and generates fewer whiffs/swing compared to other pitchers' curves. His change is a real worm killer that generates an extreme number of groundballs compared to other pitchers' changeups, has surprising cut action and is slightly firmer than usual. His slider (take this with a grain of salt because he's only thrown 5 of them in 2018) is thrown extremely hard, is basically never swung at and missed compared to other pitchers' sliders, results in more flyballs compared to other pitchers' sliders and has less than expected depth.