Once feared, now largely forgotten, the gyroball retains a stubborn hold on the baseball imagination. Perhaps Red Sox closer Koji Uehara can put the pitch to rest:
Uehara finds it pretty funny that American audiences bought into the existence of the gyroball, the unhittable mystery pitch Daisuke Matsuzaka supposedly was bringing with him from Japan when he signed with the Red Sox to great fanfare before the 2007 season. “I don’t think anybody believed that,’’ he said recently. But they did, he was told. “The Japanese people are clever,’’ he said with a laugh. “They never believed that.’’
Misunderstanding. Myth. Marketing coup. What exactly is the gyroball, that esoteric, invincible pitch from the Far East that supposedly dazzled NPB batters for years before coming to our shores in Dice-K’s repertoire, promising to reshape the art of pitching, and what ever became of it? When I read Uehara’s eulogy last week—eighteen years after the gyroball’s discovery, nine years after it first caught the West’s eye, and six years after it threatened to take MLB by storm—I realized I didn’t have any answers.
It turns out that the pitch wasn’t what we thought it was. There was nothing exotic or unfamiliar about it. The story of the gyroball, the demon miracle pitch, was in fact a quintessentially American story.
The best place to start is by clearing up what the gyroball isn’t, and never claimed to be. It’s not “a pitch that breaks twice.” It doesn’t “harness different physical forces than any other pitch currently thrown.” It doesn’t require application of the pseudoscientific theory of “double-spin mechanics.”
“There was so much written about it,” recalls Alan Nathan, a physics professor at the University of Illinois and proprietor of the excellent Physics of Baseball site. “So much of it was total nonsense, it just boggled the mind.”
“It was hyped. Like anything that gets hyped, it got confused,” says then-Baseball Prospectus writer Will Carroll, who did more than anyone to create that hype.
Of course, everything surrounding Daisuke Matsuzaka felt mythic, even the stuff that was true. In 1998, as a high schooler, he threw 250 pitches over 17 innings, a day after tossing a 148-pitch shutout. The next day, he played in the outfield, “his right pitching arm wrapped in a thick layer of bandages,” and wound up throwing 15 pitches in relief. A day after that, he put up a no-hitter on 122 pitches. He seemed superhuman. That he apparently supplemented his stamina with a signature pitch, one that nobody had ever seen before, one that batters couldn’t hope to solve, seemed plausible in context.
When America first learned of the gyroball, the popular conception was nothing like what the creators had intended. Chalk it up to a translation error by Carroll, the gyroball missionary. In a 2004 article on Rob Neyer’s blog, he cited a 2001 Japanese book by Kazushi Tezuka and Ryutaro Himeno. The book itself is wild. Filled with fantastical schematics, manga-style drawings, and a wealth of technical information, it looks like nothing so much as a manual for a baseball revolution. And to these Western eyes, it is impenetrable:


(The only accessible information comes via the flipbook animation that runs through the book—rifle the pages, and a pitcher throws a gyroball.)
Carroll admitted up front that he couldn’t read Japanese, but claimed he had nevertheless been able to puzzle out the secrets of the gyroball. He described an effect achieved by coordinating rotations of the hips, shoulder, forearm, and wrist. The result, he wrote, was a pitch that in the right hands was “all but unhittable.”
As the ball leaves the hand of the pitcher throwing a gyro — or as the Japanese call it, the “shooto” — the ball comes off the middle finger with what appears to the batter as a pure counterclockwise spin. There is no snap of the wrist; it is a true “set it and forget it” pitch. The spin is an apparent rifle-like spin that keeps the ball true until it takes a severe, late left turn from a right-handed pitcher.
Let me say that again: the ball comes at the hitter looking like a hanging curve and then takes a hard, flat turn away from a right-handed batter.
This was the first American impression of the gyroball: a ball that does not move until the last second. The effect of such a pitch would be devastating. The fundamental aim of pitching is to make one pitch look like another, and the gyroball was a breaking ball that couldn’t be identified as one until it was too late.
Carroll spread the gospel of the gyroball loudly and often. He said he had seen it break as much as three feet. He said he could teach anyone the pitch in 10 minutes. He said he’d welcome an invite from MLB teams to teach it in spring training. He claimed to have helped a local high school pitcher master it. When readers expressed skepticism, Carroll responded with a post reading “this time, there should be no doubt.” It was accompanied by alleged video proof of high schooler Joey Niezer throwing a gyroball. Here’s the video. It’s impossibly grainy footage of ... something.
A CBS Evening News report on the gyroball showed higher-definition video of ... also something. But it was nothing recognizable as an innovation—certainly nothing like Bruce Sutter’s perfection of the split-finger fastball, the last new pitch to enter the baseball lexicon, some 40 years ago. Baseball folks started getting suspicious, not least because of the lack of primary sources for the claims attributed to the gyroball.
The Boston Globe couldn’t have raised an eyebrow any higher:
Given all the confusion surrounding the pitch, it’s perhaps apt that the man who has championed it in the States doesn’t speak Japanese. Yet Will Carroll managed to procure a copy of the book, and though he couldn’t read it, he deciphered the book’s myriad illustrations and drawings, and fashioned himself as something of a gyroball guru.
Yahoo’s Jeff Passan became the first American reporter to take a rigorous look at the pitch, the rumors of which led him to compare it to UFOs or Bigfoot. Though Carroll had been touting Matsuzaka as the master practitioner of the gyroball for years, it was only at the 2006 World Baseball Classic that Passan actually asked Matsuzaka about it. Matsuzaka said he didn’t have one, and wasn’t completely certain what it even was.
Oh, Matsuzaka copped to having thrown a gyroball a time or two. “Accidentally.”
Passan now believes Matsuzaka was playing coy. “Japanese players appreciate mystery,” he says. “That Dice-K could come into a new league, maybe or maybe not throwing this pitch that nobody had seen, could only play to his advantage. He was not going to take the opportunity to turn down what little advantage he could get.”
If Passan’s correct, Matsuzaka was pandering to an old habit of the game’s observers: ascribing mystical qualities to its new imports. We’ve seen it again and again as MLB has opened itself up, first domestically and now globally. Upon integration, it was Satchel Paige who was more myth than man. It was said that he told his fielders to sit down before striking out a batter. It was said he threw something called a “bee ball,” so named because the pitch would “be where I want it to be.” When the wave of Cuban defectors began in the ‘90s, each was similarly mythologized. (El Duque did not come to America on a raft, or a floating door—it was a fishing boat hired for the occasion.) Even the 168 MPH fastball of Sidd Finch, SI’s legendary April Fool’s Day hoax, owned some credibility because he had supposedly learned it in a Tibetan monastery.
It’s a thoroughly redeemable tendency, even if it occasionally leads to a little cross-cultural silliness. New baseball hotbeds with new philosophies are welcomed with open arms. In almost every other slice of society—and in most every other sport—the unknown is demonized. In baseball, it’s romanticized.
Matsuzaka’s gyroball, though, wasn’t the same as Carroll’s. In 2006, Carroll revealed that his initial story was based on an error in translation. He had mixed up the gyroball with an entirely different pitch called the shuuto. “That’s my fault,” he straightforwardly admits today. “I made a mistake.” But the initial misunderstanding has persisted for years.
The shuuto, another mysterious Japanese pitch, is the exact opposite of what Carroll had in mind. When thrown by a right-handed pitcher, it breaks inside on a right-handed batter, as opposed to the supposed gyroball, which Carroll was now saying breaks outside.
The shuuto isn’t new or unique. Its first introduction to Americans was as “the great equalizer,” the pitch that constantly bedeviled Tom Selleck in Mr. Baseball. Only the name is exotic. In MLB, the shuuto has been thrown for decades, but under a different identity. You know it as a two-seam fastball, or a circle change, or a screwball. It’s any pitch that breaks to a pitcher’s arm side. The shuuto in Japan generally falls somewhere between a change-up and a fastball in velocity, but it’s merely an umbrella term for an entire family of pitches. This unfamiliar term for an extant pitch is a big part of the confusion surrounding the actual gyroball.
So the gyroball is not a shuuto. It’s also not, as Carroll described, a deadly pitch that starts by heading straight at a batter, then dives out over the plate to catch them off balance. (That’s merely an excellent breaking ball, something Matsuzaka certainly did throw.)
“Everyone,” the pitch’s creator would later offer meekly, “kind of misunderstood.”
Alan Nathan was one of the first Americans to understand. He paid a Japanese graduate student to translate the book that Carroll had obtained, and published his early findings on the gyroball’s computer-modeled physics. They were completely sound, Nathan wrote, but the pitch turned out to be more theoretical than practical.

Here’s what a gyroball is: a ball that doesn’t break at all. And unlike a fastball, which has backspin and should appear to rise, or a curveball, which has topspin and dips exaggeratedly, a gyroball should travel while spinning perpendicular to the path of the ball—think of a football thrown with a perfect spiral. (See infographic at left, via the New York Times.)
It should fly straight and true, with a batter looking fastball swinging under it, or swinging over it if he’s expecting the curve. Complicating matters, the gyroball looks like a slider coming out of the pitcher’s hand—the “red dot” of the rotating seams appears similar—tricking hitters into anticipating a horizontal break when none is coming.
In fluid dynamics terms, the gyroball should display a Magnus force of zero. The Magnus effect describes how a ball in flight will curve based on its spin. Even if you don’t understand it, you inherently grasp it—it’s why a fly ball down the line will tail foul, or at least toward the pole. Batters grasp it, too—just about every thrown ball will have some Magnus force, and curl predictably, and they can anticipate this curl. But with zero Magnus force, the ball doesn’t behave anything like millions of years of evolution have taught us to expect flying spheres to act.
It’s not magic, says Will Carroll, bemoaning the hype and confusion which accompanied the pitch’s introduction to America. “It’s the same things which act on every pitch—gravity, air resistance, and the Magnus force.”
The idea sprang forth in 1995, as baseball trainer Kazushi Tezuka was playing with an X-Zylo gyroscope toy. Why, he wondered, could he throw the toy 600 feet, nearly twice as far as a baseball? The answer, though he didn’t know it yet, was that the gyroscope maintained a perfect spiral and flew with zero Magnus force.
Could a ball be thrown with such a perfect spiral? Tezuka sought out highly respected computer scientist Dr. Ryutaro Himeno, who was able to model such a pitch. They published their findings in their 2001 book, the one Carroll came upon. Its title translates, roughly, as “Secrets of the Demon Miracle Pitch.”
That supernatural title implies the gyroball shouldn’t exist, but does. The truth is that it can exist, but functionally doesn’t. The gyroball is theoretical, born on a computer and only appearing in the real world as a faint and usually inadvertent simulacrum. Without an actual gyroscope inside a baseball, the odds of a pitcher throwing a ball with perfect, perpendicular spin is effectively nil. A pitcher can come close to perpendicularity, and produce a ball with minimal break, but not consistently, and not as a true gyroball with zero Magnus force.
Here’s how Alan Nathan describes those close-but-not-quite-gyroballs that pop up from time to time: “Think of a spectrum, with a perfect slider with pure horizontal movement on one end, and a gyroball, with zero horizontal movement, on the other. The spin axis can fall on one extreme or the other, but almost always somewhere in between. It’s incredibly hard to throw one with zero movement.”
It’s incredibly hard to get any slider to do what you want. “If you look at PITCHf/x data for a slider’s horizontal movement,” Nathan says, “it’s not clumped tightly. It’s all over the place. It’s hard to control the spin axis.”
Pitchers can come close. Here’s high-speed video from Japan showing as close to a true gyroball as has even been captured on film. The ball is colored and marked to show the spiral. A pitch with zero Magnus force wouldn’t have even that tiny wobble.
Matsuzaka said he had thrown gyroballs accidentally—most pitchers have in their careers, or at least close enough. These pitches with minimal lateral movement, moderate velocity, and moderate dip are nothing new under the sun, and they’re almost always unintentional.
Take it from the hitter with the best eye of his generation. Jeff Passan and the New York Times’s Lee Jenkins approached Barry Bonds during 2007 spring training with a computer and a DVD of supposed gyroballs. Surprisingly, Bonds agreed to take a look. “Barry didn’t care what the media wanted from him,” Passan recalls, “but he was always interested in baseball. I think he enjoyed taking part in debunking this mystery.”
Studying the video in the Giants’ clubhouse Wednesday, Bonds took a moment to try to identify the pitch. “It looks like a little slider,” he said. Asked if it could be a gyroball, Bonds shrugged his shoulders. “I don’t know what that is,” he said.
A slider that doesn’t break. That’s pretty much all it is, and it’s already well-known to pitchers. It’s called a “backup slider,” and it’s usually a mistake. The idea of a slider is to make it look like a juicy pitch to swing at, just before it tails out of the zone. A backup slider is one that barely moves laterally. It can be an incredible weapon—put it on the inside corner, and the batter will expect it to move out over the plate and jam himself.
When former major league pitcher Dr. Dave Baldwin was told about the gyroball, he immediately identified it as a backup slider:
“It reminded me of the, what we called the backup slider when I was playing. I didn’t throw a slider but those pitchers who did throw sliders would occasionally accidentally throw a slider that didn’t fly. It’ll just go straight. [...] Batters can pick up the slider’s spin fairly easily coming out of the hand, if the batter has good enough eyesight, and so there they’re expecting something that’s just not going to happen.”
But it’s horribly risky. If a pitcher misses with a regular slider, he’ll miss well off the plate, throwing a harmless ball. Since he can’t throw it with with any consistency, though, a pitcher can’t be sure his no-break pitch (gyroball, backup slider, whatever) won’t break right into the batter’s sweet spot. Bob Gibson said the backup slider was his greatest pitch, but it was always inadvertent—he didn’t dare try to throw it on purpose because he couldn’t be sure it would do what he wanted.
(Interestingly, in Daisuke Matsuzaka’s initial time in MLB, his slider was his most reliable out pitch, despite having minimal movement both horizontally and vertically. As the years progressed and John Farrell contracted his repertoire, Matsuzaka’s slider tended to move more, no longer even superficially resembling a gyroball.)
In 2008, Nathan and Baldwin published a research paper, “An Analysis of the Gyroball,” in SABR’s Baseball Research Journal. It examined the physics of each pitch, and declared that “the backup slider has the same spin characteristics as a gyroball.”
Kazushi Tezuka’s supposed breakthrough, then, was not inventing a new pitch. It was claiming to be able to teach an old one that no one had ever been able to throw consistently. Tezuka quickly capitalized on the gyroball mythos, selling a series of books and DVDs and running baseball academies, all promising to impart the secret of controlling the uncontrollable pitch. In 2010, he was hired by Japanese pro team the Rakuten Eagles.
This sort of commodification of the gyroball’s mythic quality is a bit of a pattern. In 2007, the Red Sox released Music From The Mound, an album featuring Matsuzaka’s “favorite inspirational songs.” It included an original composition, “Gyroball,” featuring Magic Dick from the J. Geils Band on harmonica:
The rights to the song are owned by—deep breath—Danny Bernini, Meg Vaillancourt, Dr. Charles Steinberg, Jerry Remy, Don Orsillo, Magic Dick, Larry Lucchino, Nuno Bettencourt, and Loren Harriet. Notably absent: Daisuke Matsuzaka.
At any rate, I can’t find much information on Tezuka, which is a shame; in some ways, he’s the most familiar figure in all of this. His story is as old as professional baseball, and certainly just as American. He’s a guy trying to make a buck off his patent miracles.
Leaving all this aside, can it be done? Can a player actually throw a willful gyroball as part of his regular arsenal? Players want to believe. C.J. Wilson has spent years messing around with a gyroball, even once having Tezuka come out to Rangers spring training to show him the intricacies of the pitch. (Wilson has said he doesn’t use it in games, and thinks it might be bad for his arm. Will Carroll, who specializes in injuries and pitcher mechanics, says it’s conceivable that the gyroball delivery, with its snapping motion and pronounced forearm pronation, could be especially rough on a player’s elbow, but any evidence is anecdotal.)
Carroll claims that besides Wilson, there are perhaps five pitchers currently using a gyroball as we speak who don’t want it publicly known. Keeping a step ahead of the hitters is one motivation, sure, but even more than that, “they don’t want to be known as gimmick pitchers.”
Earlier this season, Jeff Passan was in the Orioles’ locker room as players were tossing around a cylindrical toy—”just winging it from one end of the clubhouse to the other.” He took a look, and it was the same X-Zylo gyroscope toy that had sparked Tezuka’s curiosity. It was Darren O’Day’s, given to him by C.J. Wilson when they were teammates in Texas. Inspiration doesn’t strike just once.
Carroll is still a huge proponent of the pitch, and still teaches it to young players. (His method is to start them out with the X-Zylo—the grip is identical.) He believes it simply hasn’t reached critical mass yet. Unlike the knuckleball, another rarely seen pitch that was passed down by stars and Hall of Famers, there’s no “gyroball king” to popularize it, as of yet.
It could happen. Theoretically, it’s a devastating out pitch, if the risk/reward ratio could be tilted far enough in the pitcher’s favor. Nathan, who dismissed the idea that anyone was using it regularly, still believes someone could master it to the point of usability. “If a pitcher could throw it on demand,” he says, “and sparingly, just enough to keep batters off balance, it would be a useful pitch.”
Carroll thinks it’ll take time to overcome the stigma that sprouted up when the myth began to fall away, but that the value of its novelty almost demands its use. “The comic books made it out to be this mystical, unhittable pitch,” he says. “But it’s not a Bugs Bunny pitch. It’s just a pitch. But it’s good because it’s different. Like if you’ve never seen a slider before, you’re not going to hit it.”
Passan doesn’t see it happening. The gyroball will always be better in theory, whether in a physicist’s model or a writer’s breathless subjunctive.
“Inside of a supercomputer, it’s the greatest thing baseball has ever seen,” he says. “On a baseball diamond, it’s the greatest thing a hitter has ever seen.”
Image by Jim Cooke.