During his first news conference in Florida at the start of the Red Sox's spring training, Matsuzaka was expecting a question about the gyroball, and when it came at the end of the session, he smiled slyly and pondered it.

"Hmm, how should I answer?" he finally said through a translator. "I was preparing some optional answers for this particular question. Should I say, 'I have that pitch?' Or should I say, 'What particular pitch are you referring to?' Or, 'Which ball are you calling a gyroball?' Overall, if I have the chance, I will pitch that ball."

Even Red Sox officials now say Matsuzaka doesn't throw a gyroball. But Carroll, for one, still believes.

"I believe Matsuzaka knows this pitch and has worked on it," he says. "I don't believe he's perfected it, but I think he can make it work enough to keep working on it."

If Matsuzaka is indeed using the pitch, it's unclear how or when he learned it. Adding further intrigue, he has hinted he came upon the pitch on his own and that Himeno and Tezuka did not use him as a model for their invention.

As for the confusion over what the gyroball does, Carroll says it stems from one simple truth about the pitch: It has multiple incarnations that are achieved by tilting the hand during delivery, in much the same way that a fastball can be made to "cut" or sink by changing the grip or the arm angle.

Carroll calls one of those incarnations the "side-force" gyroball because of its side-to-side motion -- which distinguishes it from a "pure" gyroball that drops.

But according to Yale's Adair -- who literally wrote the book on the physics of baseball -- there is a simple reason why a pure gyroball would drop, and it has nothing to do with mysticism or double-spin mechanics.

"It's just gravity," Adair says. "It's like any pitch that doesn't have the backspin of a fastball. Gravity acts on the ball and pulls it down."

Ask the baseball expert: Tony DeMarco Sox, Yankees face obstacles as rivalry renews E-mail your questions

That would make it a version of a changeup. But because of the hand-twisting motion required to throw the gyroball, hitters would know what was coming.

"So," Adair says, "it's a changeup -- but in my mind a changeup that a batter can tee off on and clobber."

Still, Carroll is unfazed by the skepticism. Since coming across the Himeno-Tezuka book in 2002, Carroll has made it his life's mission to learn everything there is to know about this pitch and to teach it. And why not? If the pitch turns out to be a big hoax, there is no harm done. But if one day the gyroball transforms the art of pitching, he will have been at the forefront of the revolution.

And besides, Carroll says, "if you could actually teach Mariano Rivera's cutter or Brad Lidge's slider, wouldn't you do it?"