Although they have not thrown an MLB pitch in 2023, Jackson Tetreault threw 365 pitches that were tracked by the PITCHf/x system in 2022, all of them occuring in the MLB Regular Season. In 2022, they relied primarily on their Fourseam Fastball (94mph) and Slider (86mph), also mixing in a Curve (82mph). He also rarely threw a Change (86mph).
In 2022, compared to other RHP:
His fourseam fastball has some natural sinking action and has slightly above average velo. His slider generates fewer whiffs/swing compared to other pitchers' sliders, has less than expected depth, has primarily 12-6 movement and results in somewhat more flyballs compared to other pitchers' sliders. His curve has primarily 12-6 movement, is much harder than usual and results in somewhat more flyballs compared to other pitchers' curves. His change (take this with a grain of salt because he's only thrown 10 of them in 2022) is basically never swung at and missed compared to other pitchers' changeups, results in more flyballs compared to other pitchers' changeups, has a lot of backspin and is slightly firmer than usual.