I agree, he did but Marciano had a well planned career, great match ups, avoided fleet footed black fighters and beat a handful of past their prime heavyweights and retired before the likes of Floyd Patterson came onto the scene but all his opponents were either retired, coming back to make money (Taxes) as in 37 year old Joe Louis who was a shell of himself. 38 year old veteran champ, Jersey "Joe" Walcott. Light heavy practically, Ezzard Charles, were the only really viable opponents for Marciano. He only had 6 title defenses against this crop of old, has beens, IMO. Truth is he was a big puncher with great stamina and a pretty decent chin, his chin was not ironclad as some would have you believe, he was rocked and floored by fairly light punchers. He was out boxed on several occasions but his tenacity kept him coming forward and swinging until the legs of his older opponents ran dry and get got their chin. He was the best of his time but it was pretty lack luster time, like the run of Tyson in the 80's, good fighters not great fighters, part time boxers and tough men. The greats there were around were past their primes. Marciano was fun to watch, great guy but vastly over exaggerated. He avoided Patterson, Ali, Nino Valdez, Liston.