In October 1961, the Bears—utilizing Shaughnessy's complex, shifting defensive alignments—stifled San Francisco 49ers coach Red Hickey's new shotgun formation, 31–0. Chicago had learned lessons against the Baltimore Colts who had attempted to use the shotgun the previous week. Shaughnessy explained his Chicago defensive scheme in November 1961:"We can adjust to fit three things. We have defenses to fit the we face, the personnel we face and the situation in the game. Bill George calls the basic overall defense. Then Fred Williams calls the defense for the rush men. Richie Petitbon calls the defense for the backs. All of these are real bright boys, and they do a great job."