Boston Red Sox
Seth Martinez has thrown 4,314 pitches that have been tracked by the PITCHf/x system between 2021 and 2026, including pitches thrown in the MLB Regular Season and Spring Training. In 2026, they have relied primarily on their Slider (79mph), also mixing in a Fourseam Fastball (91mph), Sinker (90mph), Cutter (87mph) and Change (85mph).
In 2026, compared to other RHP:
Their slider comes in below hitting speed, sweeps across the zone, results in more flyballs compared to other pitchers' sliders and has less than expected depth. Their fourseam fastball has heavy sinking action, generates more whiffs/swing compared to other pitchers' fourseamers and has slightly below average velo. Their sinker has heavy sinking action, has less armside run than typical and has slightly below average velo. Their cutter (take this with a grain of salt because they've only thrown 18 of them in 2026) is an extreme flyball pitch compared to other pitchers' cutters, generates fewer whiffs/swing compared to other pitchers' cutters, has slightly below average velo and has some natural sink. Their change (take this with a grain of salt because they've only thrown 17 of them in 2026) dives down out of the zone and generates fewer whiffs/swing compared to other pitchers' changeups.