Non-MLB
Although they have not thrown an MLB pitch in 2024, Randy Rosario threw 1,127 pitches that were tracked by the PITCHf/x system between 2017 and 2020, including pitches thrown in the MLB Regular Season and Spring Training. In 2020, they relied primarily on their Sinker (92mph) and Slider (85mph), also mixing in a Fourseam Fastball (93mph). He also rarely threw a Change (86mph).
In 2020, compared to other LHP:
Their sinker has heavy sinking action, is a real worm killer that generates an extreme number of groundballs compared to other pitchers' sinkers, has surprisingly little armside run and has slightly above average velo. Their slider results in more flyballs compared to other pitchers' sliders, is much harder than usual and has some two-plane movement. Their fourseam fastball (take this with a grain of salt because they've only thrown 6 of them in 2020) has heavy sinking action, is basically never swung at and missed compared to other pitchers' fourseamers, is an extreme flyball pitch compared to other pitchers' fourseamers, has much less armside movement than typical and has slightly above average velo. Their change (take this with a grain of salt because they've only thrown 3 of them in 2020) generates an extremely high number of swings & misses compared to other pitchers' changeups, dives down out of the zone, is an extreme flyball pitch compared to other pitchers' changeups and is much firmer than usual.