Few players in the history of American sports have ever been more beloved than Yogi Berra, who turned 90 years old on May 12, 2015. Berra was a three-time AL MVP and a 10-time World Series champion during his playing career, all but four games of which were spent with the Yankees. As a manager he led both the Yankees and Mets to World Series appearances. His greatest legacy, though, may be as the man who contributed more unforgettable quotes than anyone in baseball history, most notably "It ain't over til it's over." While he may not have said all the things attributed to him, it's clear that they contribute to a legacy that will live even longer than the Hall of Famer himself. In celebration of his 90th birthday, we present these rare SI photos of Yogi.