Rob Zastryzny has thrown 1,671 pitches that have been tracked by the PITCHf/x system between 2016 and 2023, including pitches thrown in the MLB Regular Season, The World Baseball Classic and Spring Training. In 2023, they have relied primarily on their Fourseam Fastball (93mph), Cutter (88mph) and Slider (82mph), also mixing in a Change (81mph). He also rarely throws a Sinker (91mph).
In 2023, compared to other LHP:
Their fourseam fastball has much less armside movement than typical, generates more whiffs/swing compared to other pitchers' fourseamers, has some natural sinking action, results in somewhat more groundballs compared to other pitchers' fourseamers and has slightly above average velo. Their cutter has heavy sink, is a real worm killer that generates an extreme number of groundballs compared to other pitchers' cutters, has sweeping cut action and has slightly above average velo. Their slider sweeps across the zone. Their change results in somewhat more flyballs compared to other pitchers' changeups and has some natural sink to it. Their sinker (take this with a grain of salt because they've only thrown 2 of them in 2023) is basically never swung at and missed compared to other pitchers' sinkers, is an extreme flyball pitch compared to other pitchers' sinkers and has less armside run than typical.