Jake Arrieta has thrown 11,680 pitches that have been tracked by the PITCHf/x system between 2008 and 2015, all of them occuring in the MLB Regular Season. In 2015, he has relied primarily on his Sinker (95mph) and Slider (91mph), also mixing in a Curve (81mph) and Fourseam Fastball (95mph). He also rarely throws a Change (90mph).
Basic description of 2015 pitches compared to other RHP:
His sinker generates a very high amount of groundballs compared to other pitchers' sinkers, generates more whiffs/swing compared to other pitchers' sinkers, has well above average velo, has less armside run than typical and has little sinking action compared to a true sinker. His slider is thrown extremely hard, results in many more groundballs compared to other pitchers' sliders and has less than expected depth. His curve has an exceptional bite, generates a high number of swings & misses compared to other pitchers' curves, is slightly harder than usual and results in somewhat more flyballs compared to other pitchers' curves. His fourseam fastball results in many more groundballs compared to other pitchers' fourseamers, has slightly above average velo and has slightly less natural movement than typical. His change is thrown extremely hard, has an obvious armside fade, is an extreme flyball pitch compared to other pitchers' changeups and has some natural sink to it.