1 definition by devin_

This is a baseball pitch that gets the kind of spin similar to a spiral thrown by a quarterback in American football.
There is much debate as to whether the pitch actually exists, but Japanese pitcher Daisuke Matsuzaka allegedly throws such a pitch, similar to the slurve(cut fastball/slider) but he is usually extremely vague, saying that he has only seen the gyroball-- in japanese comic books.

www.youtube.com/watch?v=PQCbvYwHPoA

This is NOT my website, but there are a number of sketchy videos on the internet such as this where it is unclear what kind of spin is on the ball. If and when Daisuke Matsuzaka signs with a major league baseball team(as of october, 2006 he has only pitched in japan), people will surely be talking about the gyroball.
The gyroball is a mythical pitch in baseball that like bigfoot, may or may not exist.
by devin_ November 1, 2006
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