The Boston Red Sox made it abundantly evident last autumn when they appointed Andrew Bailey as pitching coach and Craig Breslow as chief baseball officer that enhancing the team’s pitching infrastructure would be a high focus. Prior to his hiring, Breslow held positions as assistant general manager and—perhaps more crucially for our purposes—vice president of pitching for the Chicago Cubs, while Bailey served as the San Francisco Giants’ pitching coach from 2020 to 2023.
It made perfect sense for the Red Sox, a team that has struggled in recent years with pitching, to choose a pitching-focused executive to run the team and assign a new pitcher to the Major League Baseball (MLB) level. The hirings suggest that the Red Sox will be making some significant adjustments to their pitching development, strategy, and execution plans, both in the minor leagues and in the major leagues.
While the Red Sox are revamping their pitching staff, the new management will also need to assess whether any progress from the previous team can be salvaged. One that might be taken into account is the team’s projected rise in cutter usage in 2023.
The Milwaukee Brewers, who previously employed Corbin Burnes, a top-of-the-rotation starter known for being one of the best cutters in baseball and throwing a lot of them, were the only team to throw a higher percentage of cutters (13.8 percent of pitches thrown) than the 2023 Red Sox, who were also part of a subtle but noticeable trend throughout MLB. Returning to the Red Sox’s utilization of the offering, to put that 2023 figure in perspective, in 2022 they used just 5.4 percent of cutters, tying for 19th place among MLB clubs.
But was it really working to throw more cutters? Yes, without a doubt—especially when compared to every other kind of pitch the Red Sox pitchers threw throughout the previous season. The Red Sox not only ranked third in MLB in cutter runs above average (14.3), but their staff also failed to record a run above average with any other pitch except curveballs, where they managed a pitiful 0.4 runs above average.
Boston Red Sox vs. Houston Astros
Not every pitcher shared the Red Sox’s adoration of the cutter, as can be seen by looking past the entire staff. Rather, it was a bullpen-primarily tendency. Of course, there’s a clear perpetrator behind it. There would inevitably be a rise in the use of cutters once the Red Sox signed Kenley Jansen to a full-time position before the 2023 campaign. With the exception of four seasons, Jansen has thrown his cutter more than 50% of the time in every season since making the big leagues in 2010. It has been his go-to weapon since then.
It’s interesting to see that Jansen’s cutter usage had begun to decline slightly prior to 2023. Do you recall the four seasons in which he failed to throw the ball 75% of the time? This period spanned from 2019 to 2022, with a low-water point of 58 percent in 2021 as a result of his increased reliance on sinkers. There is no arguing that the cutter was still Jansen’s main weapon, but in 2023, he threw more pitches than he had since 2018 and significantly reduced (forgive the pun) the amount of sinkers he used. Going that route was a wise choice, as Jansen’s cutter was the only pitch he used that had a positive run value and he was selected for the All-Star team the previous season. (It also happened in 2022).
Even while the Red Sox’s unexpected increase in cutter production and quality was largely caused by the bullpen, Jansen wasn’t the only one who organized it. The Red Sox’s two most used relievers in 2023, Chris Martin and Josh Winckowski, also relied heavily—more so than in previous seasons—on the cutter. During his rookie season in Boston, Martin threw 34.5 percent of the time with his cutter, tying his best pitch, the four-seam fastball, for a career-high percentage. In the meantime, Winckowski increased the percentage of time he used his cutter to 35.5 percent in 2023 from his debut season in 2022, slightly less than his preferred sinker. Martin and Winckowski both had remarkable success with their cutters, matching Jansen’s +11 run value and Winckowski’s +7 run value, according to Baseball Savant. In case you were wondering, those were the best scores they had ever received for their individual pitches. Winckowski’s cutter actually performed significantly better than his sinker, yielding a -4 run value.
Maddie Malhotra/Boston Red Sox/Getty Images 2024 Boston Red Sox Spring Training
The cutter didn’t have as much of an impact outside of the bullpen, although Kutter Crawford (who also made relief appearances) did contribute a little to the spike in the rotation. It’s unclear, though, if Crawford’s name obligates him to do so. Though it was a little less noticeable, Crawford’s cutter has been his second-most used pitch in each of his major league seasons, averaging between 26 and 30 percent before peaking at 28.3 percent in the most recent campaign.
That brings us to the end of last year. How about in 2024? Are there any signs that Jansen, Martin, Winckowski, and Crawford’s right arms won’t be the only places the cutter revolution spreads?
Starting with players, the Red Sox haven’t added many cutters to their rotation during a winter that has seen several tiny trades and little splash. The Red Sox could try to rely more heavily on the cutter by teaching others to throw it, as Isaiah Campbell, who they acquired in a trade with the Seattle Mariners, can throw one fairly frequently and is currently projected by FanGraphs to be in the bullpen. However, Jansen might also be traded in the near future.
Regarding pitching philosophy, I won’t claim to be aware of Breslow and Bailey’s opinions, but it’s hard to draw any firm conclusions from the results of their prior teams. The Giants finished last in cutter usage last season, while the Cubs were tied with eighth. That’s not to say Bailey would order pitchers to avoid the cutter at all costs, nor that he will make Martin and Winckowski strike out with a successful pitch, but it does cast doubt on the idea that the team will put all of its resources into producing cutter-throwing pitchers.
In the next weeks, a lot will become clear about the Red Sox’s new pitching staff’s philosophy. Naturally, the intention is not to simply assemble all of the employees from cutters (also known as Kutters). But when Breslow and company restructure the pitching team, they may decide to hang onto one of the few strategies that proved effective in 2023.
