One thing that keeps baseball fans engaged during the offseason, outside of the transactions, is the stories that come out about players. Red Sox Nation was treated to Kristian Campbell's chronicles in the Puerto Rican Winter Leagues, the usual Trevor Story offseason camp, and, most recently, Garrett Crochet learning a new pitch.
A story came out in early February that detailed Crochet spending time at his alma mater, Vanderbilt, over the offseason, learning a splitter. Crochet debuted the new pitch in his first spring training start on February 26.
The Red Sox ace isn't the only one to add a splitter this offseason, though. Making his first relief outing on February 25, Justin Slaten showed off his new splitter on against the Twins. It was two of the 15 pitches he threw, both going to lefties, resulting in a swinging strike and a groundout to second.
It's unsurprising to see some Red Sox pitchers add splitters after they shone throughout the playoffs and World Series last season. The Blue Jays and Dodgers both featured pitchers with dominant splitters that carried them to the Fall Classic. Notably, World Series MVP Yoshinobu Yamamoto, standout rookie Trey Yesavage, and veteran Kevin Gausman all featured the pitch and were incredibly successful throughout the postseason.
Justin Slaten looks to be throwing a new splitter!
— Thomas Nestico (@TJStats) February 25, 2026
Slaten is one of my favourite relievers thanks to his extreme N-S arsenal and ability to mitigate damage, and now he has a new pitch to help deal with LHH. It's deviation from his fastball helps it grade out very well! pic.twitter.com/zS48FRK5vH
Red Sox pitchers are trying to copy a championship formula
Of course, Yamamoto not only won World Series MVP, but threw two complete-game, one-run outings. Yesavage made the Yankees look silly in his postseason outing against them, getting 11 whiffs on 16 swings with his splitter, and then seven in 10 swings against the Dodgers. In 2025, Gausman led all pitchers in percentage of splitters thrown in the regular season at 37.6%, over 10% higher than anyone else. He posted a 3.59 ERA in 193 innings.
Seeing Red Sox pitchers add the pitch seems like a logical step after it took center stage in October. If the Blue Jays and Dodgers can ride the pitch to the World Series, why shouldn't the Sox try to emulate that to have greater success in 2026?
According to Driveline Baseball, splitters are best used as a change of pace pitch, used to get whiffs and induce ground balls. Crochet and Slaten both have very effective fastballs, so adding a split to their arsenal should only improve their swing-and-miss ability.
Last season, the Sox only had five pitchers throw 25 or more splitters, and four of them won't be pitching for Boston in 2025. Two have already revealed their newest pitch. It shouldn't come as a surprise if a few more pop up throughout the year. For now, seeing the Red Sox ace try to improve his dominance, and a key bullpen arm try to solidify himself in the back end of the 'pen, should be exciting for Red Sox Nation.