Gio Gonzalez has thrown 33,611 pitches that have been tracked by the PITCHf/x system between 2008 and 2020, including pitches thrown in the MLB Regular Season, the MLB Postseason, The World Baseball Classic and Spring Training. In 2020, he has relied primarily on his Fourseam Fastball (90mph) and Change (83mph), also mixing in a Curve (77mph) and Sinker (90mph). He also rarely throws a Slider (86mph).
Basic description of 2020 pitches compared to other LHP:
His fourseam fastball has some natural sinking action, has essentially average velo, results in somewhat more flyballs compared to other pitchers' fourseamers and has slightly less natural movement than typical. His change is a real worm killer that generates an extreme number of groundballs compared to other pitchers' changeups, generates a high number of swings & misses compared to other pitchers' changeups and has some natural sink to it. His curve has an exceptional bite, has sweeping glove-side movement, generates a high number of swings & misses compared to other pitchers' curves and is an extreme flyball pitch compared to other pitchers' curves. His sinker generates more whiffs/swing compared to other pitchers' sinkers and has less armside run than typical. His slider (take this with a grain of salt because he's only thrown 8 of them in 2020) is basically never swung at and missed compared to other pitchers' sliders, results in more flyballs compared to other pitchers' sliders, is much harder than usual and has less than expected depth.