It has been widely stated that Clay's antics were a deliberate form of psychological warfare designed to unsettle Liston by stoking his anger, encouraging his overconfidence and even fueling uncertainty about Clay's sanity. As Clay himself said, "If Liston wasn't thinking nothing but killing me, he wasn't thinking fighting. You got to think to fight." Former World Heavyweight Champion Joe Louis said, "Liston is an angry man, and he can't afford to be angry fighting Clay." Clay's outbursts also fed Liston's belief that Clay was terrified (something Clay's camp did little to disavow). Clay said later, "I knew that Liston, overconfident that he was, was never going to train to fight more than two rounds. He couldn't see nothing to me at all but mouth." In contrast, Clay prepared hard for the fight, studying films of Liston's prior bouts and even detecting that Liston telegraphed his punches with eye movement.