Stephen Strasburg has thrown 15,200 pitches that have been 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 has relied primarily on his Fourseam Fastball (96mph), also mixing in a Change (90mph), Curve (82mph) and Slider (91mph).
Basic description of 2017 pitches compared to other RHP:
His fourseam fastball is a real worm killer that generates an extreme number of groundballs compared to other pitchers' fourseamers, has well above average velo and has slight armside run. His change is thrown extremely hard, generates a high number of swings & misses compared to other pitchers' changeups, has slight armside fade and has some natural sink to it. His curve has sweeping glove-side movement, is much harder than usual, results in many more groundballs compared to other pitchers' curves and has a sharp downward bite. His slider is thrown extremely hard, is a real worm killer that generates an extreme number of groundballs compared to other pitchers' sliders, is basically never swung at and missed compared to other pitchers' sliders and has much less depth than expected.