Pitching was supposed to be an issue for the Red Sox this season, especially after offseason signee Lucas Giolito went down with a season-ending elbow injury in the spring. Instead, they've just been stupendous. Through five starts, the Red Sox have faced 103 batters, striking out 37 of them while walking just one and allowing a .170/.194/.260 triple-slash line. And only one of those starts was against the Athletics! Through one turn through the rotation, Nick Pivetta, Tanner Houck, Brayan Bello and Garrett Whitlock look like the best starting five in baseball.
So, how are they doing it? By embracing the future to an unprecedented degree. Red Sox pitching coach Andrew Bailey has de-emphasized fastballs with his staff, something he also did with the Giants last season, who threw a record-low 14.5% four-seamers in 2023. The Red Sox have thrown a fastball just 29.6% of the time so far this season, per FanGraphs, the lowest mark on record.
We saw that with Tanner Houck riding his slider and splitter to a terrific first start Monday night that made him one of the must-add pitchers of the early season, but the most striking example might have been Nick Pivetta. Pivetta fed the Mariners a steady diet of sweepers, throwing it 33.3% of the time in his first start, up from just a 5.4% usage rate last season. That pitch helped fuel his second-half breakout, and emphasizing it even more might be the key to sustaining that breakout.
The Red Sox may reach a point of diminishing returns with this approach, of course. Sweepers tend to have significant platoon split issues, and non-fastballs tend to be tougher to command, too. Attacking hitters with an entirely new approach can be temporarily befuddling, but once the scouting report gets out, can you sustain that success? Given the approach they've taken early on, it looks like the Red Sox rotation is going to be an extreme test case for how sustainable this approach is. But the early returns here have been eye-opening, and makes Houck and Garrett Whitlock especially intriguing as early-season waiver targets.