A gyroball is a kind of fastball or the physical phenomenon itself. The name is given to a unique baseball pitch used primarily by players in Japan.


The gyroball was developed by a Japanese scientist, Ryutaro Himeno(姫野竜太郎), and a baseball instructor, Jonathan Paruk(手塚 一志), who used computer simulations to create a new style of delivery intended to reduce stress on the pitcher. They published their work in a book, currently available only in Japan, whose title is roughly translated as, The Secret of the Miracle Pitch.

Tezuka got the idea in 1995, when he found an American toy in a Japanese store. The toy is called the X-Zylo Ultra, and its reliance on the gyroscopic effect allows it to fly more than 500 feet when thrown.[1]

Amid many conflicting claims, Tezuka says the gyroball has been misunderstood.[2]


According to Himeno and Tezuka, a gyroball is thrown so that, at the point of release, instead of having the pitcher's arm move inwards towards the body (the standard method used in the United States), the pitcher rotates his arm so that it moves away from his body, toward third base for a right-handed pitcher and toward first base for a left-handed pitcher.

However, the technique to throwing the gyroball is all in the legs, not in the unique grip of the baseball. Kazushi Tezuka is an instructor at the Jyoutatsuya baseball dojo in Tokyo, and Osaka, Japan. "This," says Tezuka, as he grabs his thigh, "is the most important part of throwing the gyroball. It has nothing to do with the hands."[3]

The unusual method of delivery creates a bullet-like spin on the ball with the axis of spin in line with the direction of the throw, similar to the way an American football is thrown. According to Tezuka, the pitch, if thrown correctly, is meant to fly straight like a fastball. In baseball, most pitches are thrown with backspin, like the usual fastball, or with a more forward spinning motion, like the curveball and the slider.

Batters use the arm speed of the pitcher and the spin on a baseball, highlighted by the seams, to judge the speed and movement of the ball. The gyroball is thrown with the arm speed of a usual fastball but goes slightly slower or faster, and since it has a bullet-like spinning motion, on occasion (when the seams are hidden from view of the batter) it will make experienced batters swing wildly at the ball. The strategy behind the gyroball is that after throwing many variations of balls, the gyroball is thrown, and thinking that the spin on the ball means that it is much slower or faster, the batter would try to adapt the wrong speed. But since the gyroball exceeds their expectation, the batter's hit is incorrect, and a strike can easily be achieved.

The gyroball is also often confused with a completely different Japanese pitch called the shuuto, due to an error in a well-known article by baseball writer Will Carroll[4]. Although Carroll later corrected himself, the confusion still persists.

In the video game MLB 07: The Show, only Daisuke Matsuzaka (listed as "Tate Baik") has the ability to throw the gyroball, although the movement of the pitch in the video game differs from the movement of the actual pitch.

A careful computer analysis of Matsuzaka's pitches for the Boston Red Sox for the first half of the 2007 season by Dan Fox of Baseball Prospectus suggests that while Matsusaka commands a dazzling array of pitches, the gyroball is more myth than reality, however, Dice-K has said he is trying to learn to throw the trick pitch.[5]


Official gyroballersEdit

  • Tetsuro Kawajiri (retired): He is supposed to be a typical gyroballer. According to the book, the authors confirmed he threw a two-seam gyroball.[6] It confuses the batter by giving the illusion that the ball is faster than it actually is, because of the greater difference between the start speed and end speed. The batter cannot adapt to the slower end speed, which is not what he expected. The gyroball is often confused with a changeup, but the beginning speed is the same as a fastball.[7]
  • Shunsuke Watanabe (Chiba Lotte Marines): He and Tezuka officially allowed him to be a gyroballer,[8] he throws a two-seam gyroball.[9]He thought it was just a non-breaking curveball before Tezuka told him it was the gyroball.[10]He throws four-seam gyro as well.[11]
  • Tomoki Hoshino[12] (Seibu Lions)
  • Nobuyuki Hoshino (retired): According to Tezuka, their fastball has a four-seam spiral movement. This is the four-seam gyroball. The nature is opposite to two-seam, the batter may confuse it as being much slower initially. Tezuka pointed it out in "スポーツトレーニングが変わる本" which means The book which changed a way of sports training. Especially Nobuyuki, he was supposed to be a typical slow baller, nevertheless, Norihiro Nakamura thinks his fastball was the fastest in Japan, much better than even Matsuzaka's. Since they both are left-handed, the moving direction is opposite to the other pitchers.


  • Daisuke Matsuzaka: According to the result of analysis by high-speed photography, from the batter's view, his forkball-like slider rotates in a counterclockwise direction (clockwise from pitcher), and it is explained that the gyro axle is inclined.[13] However, Tezuka and Himeno have different conclusions. Himeno says it is not just a slider but definitely a kind of gyro,[14] because the gyro has a strong possibility of making different big curves (like slider, shuuto, or forkball) as well as speed illusion when the gyro axle is inclined.[15]That is why Matsuzaka is supposed to be a gyroballer, but Tezuka insists it is a little bit different. Tezuka thinks gyroball is an "unexpected ball" and basically it is not a breaking ball, it does not move at all.[16] although it is quite close to a slider[17][18], [19]Seemingly, Matsuzaka himself agrees with Tezuka's opinion and he does not think he is a real gyroballer.[20] He said, "Looks like they are talking about my cut fastball or sinking slider. I guess sometimes it has a similar rotation of a gyro, when I fail to throw the cut fastball or the slider properly, but it is not exactly a gyro itself. It is different. There is a particular way of throwing it. I guess it is a kind of shuto-like cut fastball. I can't throw it like consciously, but occasionally I throw it accidentally. It seems to be rising, and the speed appears accelerated close to the batter. Nobody hit it before."[21][22]Actually Seibu Lions's catcher, Tooru Hosokawa said Matsuzaka occasionally throw strange cut fastball with gyro-spiral, it drops lengthwise,or turns aside, or rise up.[23]In addition, some players who played with him in Seibu Lions testified he sometimes throws it (Tezuka's gyroball) when he plays catch, so even Tezuka affirms the possibility.[24]
  • Hideo Nomo: Tezuka says most likely he throws it.[25]
  • Jered Weaver: His fastball is considered probably the four-seam gyro.[26].
  • Jeff Weaver: His slider sometimes does not curve, but rise (illusion), it is sufficient to be the two-seam gyro.[27]
  • Pedro Martinez: Tezuka thinks he throws it accidentally.[28]
  • Roger Clemens: Kazuo Matsui reckons he may throw it because his fastball has a gyroball-like rotation.[29]
  • C.J. Wilson: He is trying to master the gyroball.[30]However, as for his two-seam ball, it is sometimes very similar to slider or sinker in spite of his adoption of Tezuka's theory, he can not control it. He guesses because the gyro axle is inclined in irregularity.[31]
  • Jeff Samardzija: Tezuka says he probably throws it because he is used to throwing a football, and the spin is the same.[citation needed]
  • Kids: For example, Akinori Otsuka said his nine-year old child throws a gyroball-like ball even though Otsuka himself can not throw it.[32]Tezuka thinks many kids throw it unconsciously before their instructors modify their natural pitching form.[33]

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