File:Mariano Rivera's cutter grip traced onto ball for Roy Halladay at Baseball Hall of Fame.jpg - Wikipedia

At the 2008 All-Star Game, Mariano Rivera taught Roy Halladay his famous cutter. Halladay traced the outline of the grip onto the ball, and kept it in his locker for the rest

Championship Year in Review: From April to October, in their own words - Giants Extra

What Mariano Rivera Shared With Roy Halladay, Besides Hall of Fame Credentials - The New York Times

Mariano Rivera - Wikipedia

Roy Halladay - Wikipedia

Mariano Rivera's Cutter and the Nastiest Pitches in Baseball, News, Scores, Highlights, Stats, and Rumors

Remembering Mariano Rivera's final game - Pinstripe Alley

Mariano Rivera's Cutter and the Nastiest Pitches in Baseball, News, Scores, Highlights, Stats, and Rumors