The Japanese Gyroball Mystery - The New York Times

An Analysis of the Gyroball – Society for American Baseball Research

Not Much to Matsuzaka's Mystery Pitch - The New York Times

E-Ticket: Chasing the Demon Sphere

CR4 - Blog Entry: Baseball's Bigfoot: The Gyroball

Matsuzaka's First Pitch Is Welcome Relief for Red Sox - The New York Times

Greatest Pitches in Baseball Of All Time – Legends Clothing Co.

Hideki Irabu's complicated life and tragic end - Sports Illustrated

E-Ticket: Chasing the Demon Sphere

Not Much to Matsuzaka's Mystery Pitch - The New York Times

E-Ticket: Chasing the Demon Sphere