Although they have not thrown an MLB pitch in 2023, Ronald Bolaños threw 878 pitches that were tracked by the PITCHf/x system between 2019 and 2022, including pitches thrown in the MLB Regular Season and Spring Training. In 2022, they relied primarily on their Sinker (93mph), Slider (84mph) and Fourseam Fastball (94mph), also mixing in a Curve (78mph). He also rarely threw a Change (87mph).
In 2022, compared to other RHP:
His sinker has surprisingly little armside run, results in somewhat more groundballs compared to other pitchers' sinkers and has slightly above average velo. His slider is an extreme flyball pitch compared to other pitchers' sliders, generates more whiffs/swing compared to other pitchers' sliders, has short glove-side cut and has some two-plane movement. His fourseam fastball is a real worm killer that generates an extreme number of groundballs compared to other pitchers' fourseamers, has some natural sinking action, has essentially average velo and has slightly less natural movement than typical. His curve results in somewhat more flyballs compared to other pitchers' curves and has slight glove-side movement. His change (take this with a grain of salt because he's only thrown 16 of them in 2022) is basically never swung at and missed compared to other pitchers' changeups, is much firmer than usual and results in more flyballs compared to other pitchers' changeups.