The inside story of the sweeper field made famous by Shohei Ohtani
To some within the Yankees, it was just a pinched slider. Some saw it as a sweeping slider. At one point, the organization called it a “whirly”, acknowledging that it was an entirely new offering.
The new field – which isn’t really a new field – has officially made its way into the major league lexicon and gone mainstream as a sweeper.
This season, MLB’s Statcast has taken on a cult pitch and been introduced to the wider baseball world, now appearing on scoreboards, statistics websites and TV broadcasts with its own distinct rating.
Last season, the Yankees’ Clay Holmes threw two different forms of breaking throws, one with more horizontal movement (the sweeper) and one with more depth (the slider). He hasn’t changed his arsenal this year, but according to the pitchlogs, he now has a new offering.
The Yankees were early adopters of the field in their development ranks, so let’s ask them: What exactly is the sweeper?
“I look like I’m throwing a sideways curveball,” said reliever Greg Weissert, who has thrown 38.4 percent sweepers this season.
Imagine the dive of a curveball, but executed horizontally instead of vertically. A sweeper is a breaking throw that shoots more sideways than a typical slider and – thanks to the seams of the ball, but more on that later – appears to rise simply because it doesn’t fall much. The very best sweepers, like Shohei Ohtani’s, can travel 20 inches from right to left for a right-handed thrower.
“Most importantly, it just doesn’t move the way you expect the ball to move a lot,” said Yankees pitching coach Matt Blake. “It just has more horizontality [movement], but it doesn’t go down as much as you expect. It usually stays above the barrel.
Blake first learned about the field when he was the pitching coordinator at Cleveland, where Corey Kluber used the sweeper to win a pair of Cy Young Awards in the mid-2010s. Trevor Bauer grabbed his rotation buddy’s gun. Mike Clevinger also started trying it out and it started to spread within the organization.
However, Cleveland was not alone. The forward thinking Dodgers and Astros have also discovered and taught the revelation. Others had happened on the field independently, including longtime reliever Adam Ottavino, a Brooklyn native who grew up watching David Cone, Orlando “El Duque” Hernandez and Jeff Nelson frustrate hitters with snapping breaking balls.
Ottavino picked up his version of the sweeper and combined it with a more traditional slider, then made it to the majors in the early 2010s and found that the sweeper worked better.
“It’s a really big, horizontally breaking slider,” said Ottavino, now in a heavy Mets bullpen with Jimmy Yacabonis and Brooks Raley. “I didn’t invent it, but I probably used it more times than anyone in ’14, ’15, ’16, ’17.”
The filth of the field was evident before physics.
The Yankees began learning to supplement pitchers’ arsenals with two-seam fastballs, using a similar grip that plays with the seams.
“I don’t think there was a lot of information about why it worked that way or how guys did it — only Kluber did it, and then the guys sort of replicated that,” Blake said. “And then here [with the Yankees]we started learning more about it just in terms of the seam orientation and some of the spin effects from which the seams are aligned.
High speed cameras have changed the game and made an art more of a science. Observable forces at play when a baseball is thrown are traditionally known as gravity, which forces the ball down, and what is known as the Magnus effect, where, for example, a pitch with backspin fights gravity and stays up longer, while a topspin pitch embraces gravity and dive.
In recent years, the proliferation of technology has made it possible to study another phenomenon. Dr. Barton Smith, a professor at Utah State University, has published studies on what’s called “seam-shifted wake,” which is more about axis and less about spin frequency. The idea is that the seams of the ball also interact with the air and play with its direction. A correctly thrown sweeper (or two-seam) can use the seams to fight gravity.
“We’re looking at it from one lens,” Blake said, the “we” including Yankees assistant pitching coach and pitch designer Desi Druschel and senior director of pitching Sam Briend. “Barton Smith looked at it from a different lens, more of a physics lens. And then we saw it just by watching guys pitch, and then there was kind of a qualitative look at some of the more objective information.
The Yankees have thrown the fourth most sweeps in all of baseball this season, and their minor league system is filled with practitioners off the field. Nestor Cortes, Schmidt, Holmes, Weisset, Michael King and Wandy Peralta cast the tone that science may not have invented, but it helped define.
The sweeper works best against equilateral batters – a right pitcher wants it to dance away from a right batter. According to Schmidt, who throws his version at an average speed of 86.6 mph, between a slower curveball and a faster cutter and two-seamer, the key is in the speed. The movement will be there, but a slower version will be easier to pick up.
“I’ve had a lot of success with mine because I throw it pretty hard, and it has eight to nine inches of horizontal [movement]which is on the up end,” said Schmidt, whose sweepers have kept hitters at a .250 average this season.
Overall, pitch was more effective than most. Major league hitters hit .202 against sweepers this season with a .364 slugging percentage. Against all other pitches, batters hit .247 and slugging .404.
But the secret is out and it has a name. The more sweepers see hitters, the better they will adapt.
The cutting-edge organizations no longer have the advantage they had a few years ago, when only a few throwers had a weapon that kept moving sideways and fighting gravity.
“Like anything, the more you see that field, the less unpredictable it is,” Blake said. “People are just starting to train their eyes on it.”
So what’s the next sweeper?
“Good question,” said Blake. “I think we’re still looking at that.”
– Additional reporting by Mike Puma