What's a gyroball?

# What's a gyroball?

Nov. 10 2006 4:11 PM

# What the Heck Is a Gyroball?

## A Japanese baseball pitch comes to America.

Ace pitcher Daisuke Matsuzaka is being auctioned off by his Japanese baseball team this week. Early reports indicate that major-league clubs may be willing to pay \$40 million or more for the rights to negotiate with Matsuzaka, who is supposed to be able to throw a mysterious pitch called the gyroball. What is the gyroball?

A breaking pitch that's similar to a slider or a cut fastball. (Click here for a slow-motion video.) What gives the pitch its mystique is how it came to be: The gyroball was devised by Japanese scientist Ryutaro Himeno, who described the results in his 2001 book Makyuu no Shoutai, which translates roughly to The Secrets of the Miracle Pitch. Himeno had been modeling the movement of different pitches on a supercomputer, then decided to use his equipment to come up with something new.

The pitch he invented gets its name from its spin, which is like that of a football spiral. (Himeno calls it "gyro spin.") Most pitches in baseball either have topspin or backspin, but the gyroball spins sideways, like a thrown football or a bullet fired from a rifle.

There's some disagreement, however, about what the gyro spin actually does.

According to physicists, the gyroball should drop more quickly than a fastball. A standard fastball is thrown with backspin, which creates a lift force that keeps the ball in the air. A cut fastball has a lot of backspin with just a little sidespin to make it "curve," or break to the side. But the gyroball spins sideways with just a little backspin. That should make it break like a cut fastball and drop more quickly. (The gyroball won't drop quite as much as a curveball, which is thrown with topspin.)

In practice, the pitch may have more of a break than a drop. Baseball Prospectus writer Will Carroll, who has preached the gyroball's virtues for years, says he's seen the pitch curve 12 to 18 inches without much sinking motion at all.