Demon Sphere Gyro Ball

So I was looking at this article in Popular Mechanics that purports to explain what a Gyro Ball is, and how it's thrown - specifically, how it's thrown by Japanese free-agent and (hopefully) future pitcher for the Mets, Daisuke Matsuzaka. There's this helpful little diagram that shows the various spins on three different pitches (curveball, slider, and gyro ball) and a series of lines that indicate how each pitch is supposed to move. Great.

The pitch is apparently the product of something called Double Spin Mechanics, invented by a couple of Japanese scientists who were trying to come up with a way for pitchers to reduce the stresses of throwing a baseball. The double-spin system supposedly allows the pitcher to impart a rifle-like spin on the ball, which somehow causes the pitch to move laterally from the third base to the first base side (when thrown by a right-hander) – the pitch "takes a left turn and heads to the dugout.” Sounds great. This is almost all from a report that Will Carroll, who ordinarily writes about sports injuries for Baseball Prospectus, wrote on sabermetrician Rob Neyer’s website.

Except for three things. One, Daisuke doesn't throw the gyro ball. When asked about the pitch while he was in the US for the World Baseball Classic this spring, D-Mat claimed that he doesn’t throw it, but that he’s trying to learn – he’d like for it to be his out pitch. Specifically, Daisuke says that he’s thrown it a couple of times in games “but not too much. Sometimes accidentally.” And this guy is supposed to be the master of the gyroball?

Two, Will Carroll apparently gets the gyroball confused with the shuuto, a pitch thrown by a lot of Japanese players that acts kind of like a screwball/reverse cut fastball, and moves towards third base when thrown by a right-hander. Though that's probably nitpicking.

And third, if you look at the spins in that Popular Mechanics diagram, they’ve got the spin for a slider backwards. Yep. Look, the only way to get a baseball to do anything, other than move in a straight line, is to put some kind of spin on it, and physics says that the ball will move in the direction of its rotation (as seen from the batter’s box). Rotation from top to bottom, that’s a curveball. Rotation from bottom to top, that’s a “rider,” or rising fastball (which of course doesn’t actually rise, that’s an optical illusion – it just doesn’t drop as much due to gravity as it should). That “slider,” is a screwball. If the ball, as seen in that diagram, rotates from right to left, it would have to move that way – towards the batter, not away.

As Neyer and James said in their great Guide to Pitchers, there are two ways of describing what a pitch is: you can describe the manner in which a ball is gripped and the motion with which it is thrown, or you can describe what the pitch does on its way to the plate. For example, the two-seam fastball, overhand curve, and nickel curve are also known as the sinker, 12-to-6 curve, and slider. I don’t think that the gyroball really exists. I think it’s just a slider with extreme lateral movement, or a really good cut fastball. But here’s what Al Leiter has to say:

Alright, so he has a curveball grip and he pulls down on the ball. I threw one of these and I called it a cutter. They can call it what they want. It's a cut fastball.

Finally, while I was out checking on the internets double-checking to make sure that PM’s slider rotation was wrong, I found different and occasionally contradictory instructions for how to throw a slider here, here, and here. I’m not sure anybody knows what they’re talking about. Which is why pitchers are sort of like witch doctors – nobody knows exactly what they’re doing, but they’re definitely doing something.