Although he has not thrown an MLB pitch in 2018, Stephen Strasburg threw 17,625 pitches that were tracked by the PITCHf/x system between 2009 and 2017, including pitches thrown in the MLB Regular Season, the MLB Postseason and Fall/Winter Ball. In 2017, he relied primarily on his Fourseam Fastball (96mph) and Curve (83mph), also mixing in a Change (89mph) and Slider (91mph).
Basic description of 2017 pitches compared to other RHP:
His fourseam fastball has well above average velo and has slight armside run. His curve generates more whiffs/swing compared to other pitchers' curves, is much harder than usual, results in many more groundballs compared to other pitchers' curves and has slight glove-side movement. His change is thrown extremely hard, generates an extremely high number of swings & misses compared to other pitchers' changeups, has slight armside fade and has some natural sink to it. His slider is thrown extremely hard, has much less depth than expected, generates fewer whiffs/swing compared to other pitchers' sliders, results in many more groundballs compared to other pitchers' sliders and has primarily 12-6 movement.