Idk if I ever heard people say Marciano was great defensively. Heard the opposite many times. “He was easy to hit” is a line thrown around here all to often. One I’ve always stated was inaccurate. I think the “hard to hit clean” or with combos would be accurate. When you watch his fights he rarely gets hit with a combo. I also agree with not scoring rounds using compubox . Not really there for that though and even they admit it. But it can be useful with tracking defense and accuracy. Useless in regards to who is landing the harder better shots though.
Marciano's defence consists of a being a small guy in a crouch and someone who was constantly moving. He was a hard target to hit for the subpar competition he had.
He has 4 opponents, of like 45, that most would describe as "not subpar". His average level of competition was relatively, very low. Also, Charles was very far past his prime and Moore was smaller and also past his prime.
I will add that a swarmer, is the single most difficult boxing style, for a fighter or trainer to be successful with at the highest level. If a swarmer gets to the top in their era, then a lot of things must have gone right, on both the fighter and trainers part!
Sure, most of his opponents were far from great. Doesn't change the fact that he fought against some very good fighters. Charles was past his prime, but he was still capable of beating world level boxers. Moore was just slightly past his prime and he wasn't really smaller than Marciano
Think you’re highly exaggerating. Beat probably around the average of ranked men for HW champions. Charles wasn’t anywhere near far past his prime. Obvious from the footage. Past his prime sure but more like Ali v Foreman as opposed to what you’re describing. Moore is also listed as 5”11 and inch taller then Rocky w a longer reach. They weighed the same fight night. Moore often being heavier then Rocky for his Hw fights. Moore although about two years removed from his best imo was still on the best streak of his career.
But both were top contenders in that time. These two defenses are better than most champions best defenses. Johnson and Dempsey didn't have a single comparable defense and both were ATG fighters.
I did some stats of my own on old boy Rocky. Here is a spreadsheet sorting top 10 HWs of each decade. The color coding groups those who turned pro in the same decade. Rocky cleaned up the old guard like other greats. His field of contemporaries were rather lacking though.
Is it possible to become a great fighter without having at least some defensive skill ? .... I don’t think so
Being a top contender doesn't make you prime, it may mean,and some times does, you are active in a weak era.