Red Sox Prospects Throw More Breaking Balls Than Any Other Team—Pitching Director Justin Willard Explains Why


Image credit: Red Sox pitching director Justin Willard (Photo by Maddie Malhotra/Boston Red Sox/Getty Images)
When challenging norms in any given space, it’s almost always met with a great deal of pushback. The very idea of progress can be scary to those comfortable with the status quo.
In baseball, however, the definition of “status quo” is amorphous and ever-evolving. Don’t like the prevailing wisdom or approach around a certain concept in the sport? Just give it a couple years.
This can be seen on the mound especially, where expanded analysis of advanced pitch metrics has led organizations to understand player strengths and weaknesses better than ever before. In doing so, it’s allowed player development to hone in on what players do well and track their progress in areas of weakness, facilitating even more change.
We’ve seen breaking ball types and their corresponding labels multiply in recent years. We’ve seen four-seam fastballs become all the rage and then go out of style again, replaced by sinkers and cut-ride four-seams. With this increase in breaking ball usage and decline in heaters, the fastball rate across the league in 2025 is below 45% for the first time ever. That would have been unheard of 15 years ago.
Clearly, change is everywhere in baseball. And no team in recent years has embraced challenging the status quo in the player development space quite like the Red Sox.
In the last few years, Boston’s hitting development program has received praise for the work done under hitting director Jason Ochart. The organization has seen great results across a wide range of up-and-coming hitters in recent seasons—most notably Roman Anthony and Kristian Campbell— thanks in part to putting greater emphasis on developing bat speed, improving swing decisions and optimizing ball flight. Even so, despite developing more than a handful of positional players on the Top 100 Prospects list, there have still been critics of the Red Sox methods throughout the game.
In 2025, chatter around the organization has turned to the Red Sox cache of talented pitching prospects and their unusually high breaking ball usage. Numerous scouts throughout the game tasked with coverage of Boston’s farm system noted to Baseball America that the organization’s minor league breaking ball usage was well beyond normal, even by current MLB standards.
To inspect this trend further, Baseball America obtained information on all 30 MLB organizations’ breaking ball rates. Pitches included in our collected sample included curveballs, cutters, sliders and sweepers. Results represent data from Triple-A, Double-A, High-A, Low-A and the domestic complex leagues (no Dominican Summer League) as of June 2.
The numbers confirmed what we’ve been hearing.
Through the start of June, the Red Sox were one of 10 organizations with a breaking ball usage 40% or higher. They not only led all of minor league baseball in breaking ball usage, but their 46.7% rate bested the next highest team by over two percentage points. To put this in perspective, the 15th-highest breaking ball usage belonged to the Yankees at 38.2%—nearly a 20% gap down from the Red Sox.
Organization | Breaking Ball Usage Rate |
---|---|
Red Sox | 46.7% |
Marlins | 44.4% |
Cubs | 42.4% |
Mets | 42.3% |
Astros | 42% |
Orioles | 41% |
Guardians | 40.9% |
Brewers | 40.6% |
Rangers | 40.3% |
Cardinals | 40.3% |
Twins | 39.7% |
Braves | 39.6% |
Phillies | 39.3% |
White Sox | 38.6% |
Yankees | 38.2% |
Dodgers | 38.1% |
Blue Jays | 38% |
Mariners | 37.9% |
Diamondbacks | 36.9% |
Rays | 35.5% |
Reds | 34.2% |
Pirates | 34.2% |
Giants | 34.0% |
Royals | 33.9% |
Padres | 33.5% |
Tigers | 32.2% |
Athletics | 32.0% |
Nationals | 30.9% |
Angels | 30.8% |
Rockies | 29.4% |
In order to understand the reasoning and nuance behind this approach, we spoke with Red Sox pitching director Justin Willard. As he explained, this breaking ball-heavy pitching philosophy had roots long before 2025.
“It started before our Red Sox days,” Willard said, explaining that the genesis came from Red Sox pitching Andrew Bailey’s time with the Giants and his own previous stop with the Twins.
The alignment in thinking between Bailey and Willard allowed the organization to begin to develop a pitching identity focused around a very simple but effective mantra: “Throw nasty stuff in the zone.”
“We were very aligned on the way we thought about pitching development and optimization.” Willard said. “It didn’t manifest overnight. It was something we were already doing with the Twins. Coming here, we tried to hone in on what guys strengths were.”
Objectively, fastballs were not one of the strengths of Red Sox pitchers throughout the organization at the time of Willard and Bailey’s arrival. That meant a change was needed.
“We came here and, at the time, we threw a lot of fastballs,” Willard said. “But our fastballs weren’t very good. I like fastballs; I don’t hate fastballs. They just have to be good.”
If the organization’s extreme breaking ball usage evolved from a desire to put pitchers in the best position for success, it meant helping each player in the organization to “understand what is nasty about their arsenal.”
However simple the phrase, contextualizing the concept of “nasty stuff,” is different for each player.
“Let’s develop nasty stuff,” Willard said. “Okay, what does that mean? It might be the shape of your breaking ball, increasing fastball velocity or your changeup. Are we in the zone? Are we in the quadrants we want to be? Then we layer on performance problems.”
While some in the industry might speculate the Red Sox are emphasizing breaking balls as a way to game Stuff models—which are notoriously fond of spin—and fluff the value of their pitching prospects, the alternative explanation is far more simple: A lack of quality fastballs throughout the organization and the basic idea of throwing your best pitches more often has led to a higher than normal breaking ball usage rate across the organization.
With some of the recent trends among Red Sox acquisitions, higher fastball usage among the organization’s pitchers could become more commonplace as they identify and target pitchers with better fastballs. Willard pointed to recently-acquired Kyle Harrison and Top 100 Prospect Payton Tolle as two players in the organization who will throw their fastballs at a high rate due to the quality of those pitches.
“A lot of what we look at in the draft is your release characteristics, your fastball shape,” Willard said. “(We’re) trying to take the best pitcher available and then leverage whatever they do well.”
With a greater emphasis on fastball quality in the acquisition phase, this trend within the Red Sox organization may, too, just be temporary. Change, after all, is in the modern game’s DNA.
In the end, it feels like Boston’s high breaking ball usage is as much a product of the student’s strengths as it is the teacher’s philosophy.