A gyroball is a type of baseball pitch used primarily by players in Japan.

The gyroball pitch was first identified by the Japanese scientist Ryutaro Himeno (姫野 龍太郎), and later developed into a specific throwing technique by baseball instructor Kazushi Tezuka (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, the title of which is roughly translated as The Secret of the Miracle Pitch (魔球の正体).

However, the technique to throwing the gyroball is all in the arms, 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."

Amid many conflicting claims, Tezuka says the gyroball has been misunderstood. In short, similar to a bullet, gyroball's axis of spin directly faces forward.

Daisuke Matsuzaka (松坂 大輔, Matsuzaka Daisuke^?, born September 13, 1980) is a Japanese professional baseball pitcher with the Boston Red Sox of Major League Baseball in the United States. He previously played for the Seibu Lions in Japan's Pacific League. He was selected the MVP of the inaugural and the second World Baseball Classic, and is an Olympic bronze medalist.

Matsuzaka was born on September 13, 1980, in Kanita, Aomori Prefecture. He was named after Japanese high school star pitcher Daisuke Araki. Growing up in Koto, Tokyo, he studied kendo from the age of five to nine and began playing organized baseball when he was in 3rd grade.

After excelling at the Little League and junior high level, Daisuke Matsuzaka was admitted into Yokohama High School, a baseball powerhouse, in the spring of 1996. By his second of three years, he had developed into the school's ace pitcher. Despite his early success, he would experience a setback that summer when he allowed a go-ahead wild pitch in the semi-final game of the Kanagawa Prefecture preliminary round of the National High School Baseball Championship (Summer Koshien).