Although he has not thrown an MLB pitch in 2020, Tanner Rainey threw 1,212 pitches that were tracked by the PITCHf/x system between 2018 and 2019, including pitches thrown in the MLB Regular Season and the MLB Postseason. In 2019, he relied primarily on his Fourseam Fastball (98mph) and Slider (88mph). He also rarely threw a Change (91mph).
Basic description of 2019 pitches compared to other RHP:
His fourseam fastball generates an extremely high number of swings & misses compared to other pitchers' fourseamers, is thrown at a speed that's borderline unfair, has less armside movement than typical and has some added backspin. His slider generates an extremely high number of swings & misses compared to other pitchers' sliders, has exceptional depth and is much harder than usual. His change (take this with a grain of salt because he's only thrown 3 of them in 2019) is thrown extremely hard, is basically never swung at and missed compared to other pitchers' changeups, results in more flyballs compared to other pitchers' changeups and has slight cut action.