Although he has not thrown an MLB pitch in 2020, Andrew Chafin threw 4,593 pitches that were tracked by the PITCHf/x system between 2013 and 2019, including pitches thrown in the MLB Regular Season, the MLB Postseason, Spring Training and Fall/Winter Ball. In 2019, he relied primarily on his Slider (85mph), Fourseam Fastball (94mph) and Sinker (94mph). He also rarely threw a Change (87mph).
Basic description of 2019 pitches compared to other LHP:
His slider generates an extremely high number of swings & misses compared to other pitchers' sliders, has primarily 12-6 movement and has some two-plane movement. His fourseam fastball generates more whiffs/swing compared to other pitchers' fourseamers, has some natural sinking action, has well above average velo and results in somewhat more groundballs compared to other pitchers' fourseamers. His sinker is a real worm killer that generates an extreme number of groundballs compared to other pitchers' sinkers, has well above average velo and has less armside run than typical. His change (take this with a grain of salt because he's only thrown 6 of them in 2019) is thrown extremely hard, is basically never swung at and missed compared to other pitchers' changeups, is an extreme flyball pitch compared to other pitchers' changeups, has slight cut action and has a lot of backspin.