Pittsburgh Pirates
Although they have not thrown an MLB pitch in 2023, Robert Stephenson threw 5,511 pitches that were tracked by the PITCHf/x system between 2014 and 2022, including pitches thrown in the MLB Regular Season and Spring Training. In 2022, they relied primarily on their Slider (84mph) and Fourseam Fastball (97mph). He also rarely threw a Curve (78mph) and Change (88mph).
In 2022, compared to other RHP:
His slider has exceptional depth, generates more whiffs/swing compared to other pitchers' sliders and results in more flyballs compared to other pitchers' sliders. His fourseam fastball is blazing fast, has some natural sinking action and has slight armside run. His curve is basically never swung at and missed compared to other pitchers' curves, results in more flyballs compared to other pitchers' curves and has slight glove-side movement. His change (take this with a grain of salt because he's only thrown 9 of them in 2022) 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.