Non-MLB
Although they have not thrown an MLB pitch in 2024, J.C. Mejía threw 2,275 pitches that were tracked by the PITCHf/x system between 2019 and 2023, including pitches thrown in the MLB Regular Season, Spring Training and Fall/Winter Ball. In 2023, they relied primarily on their Sinker (95mph) and Slider (85mph), also mixing in a Change (89mph) and Fourseam Fastball (95mph).
In 2023, compared to other RHP:
Their sinker has heavy sinking action, generates a high number of swings & misses compared to other pitchers' sinkers, generates a very high amount of groundballs compared to other pitchers' sinkers, has well above average velo and has slight armside run. Their slider is an extreme flyball pitch compared to other pitchers' sliders and has short glove-side cut. Their change is thrown extremely hard, results in somewhat more flyballs compared to other pitchers' changeups, has slight armside fade and has some natural sink to it. Their fourseam fastball has heavy sinking action, has slight armside run and has slightly above average velo.