Although they have not thrown an MLB pitch in 2023, Steven Brault threw 6,484 pitches that were tracked by the PITCHf/x system between 2016 and 2022, including pitches thrown in the MLB Regular Season and Spring Training. In 2022, they relied primarily on their Sinker (91mph), Fourseam Fastball (91mph) and Slider (82mph), also mixing in a Change (86mph).
In 2022, compared to other LHP:
Their sinker generates an extremely high number of swings & misses compared to other pitchers' sinkers, has less armside run than typical and has some natural sinking action. Their fourseam fastball results in more flyballs compared to other pitchers' fourseamers, has some natural sinking action and has essentially average velo. Their slider has short glove-side cut, has less than expected depth and results in somewhat more flyballs compared to other pitchers' sliders. Their change (take this with a grain of salt because they've only thrown 8 of them in 2022) is basically never swung at and missed 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.