The cover of Sports Illustrated following the 1968 Masters.
The greatest of all rules mishaps occurred at the 1968 Masters. Upon finishing the final round apparently tied for the lead with Bob Goalby, Roberto De Vicenzo noticed his playing partner had given him a four on the par-4 17th hole, even though he had made a three. The Rules of Golf state that if a player signs a higher score than played, the signed score stands. Having already signed the card, De Vicenzo gained a stroke, missing the playoff by one. De Vicenzo responded to his disastrous error stating, "What a stupid I am."