New York Yankees
Aroldis Chapman has thrown 7,544 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, The World Baseball Classic and Spring Training. In 2017, he has relied primarily on his Fourseam Fastball (100mph), also mixing in a Slider (88mph). He also rarely throws a Change (89mph).
Basic description of 2017 pitches compared to other LHP:
His fourseam fastball is a real worm killer that generates an extreme number of groundballs compared to other pitchers' fourseamers, is thrown at a speed that's borderline unfair, generates a high number of swings & misses compared to other pitchers' fourseamers, has slightly less natural movement than typical and has some added backspin. His slider is thrown extremely hard, generates a very high amount of groundballs compared to other pitchers' sliders, has much less depth than expected, generates more whiffs/swing compared to other pitchers' sliders and has short glove-side cut. His change is thrown extremely hard, is an extreme flyball pitch compared to other pitchers' changeups and has a lot of backspin.