Evander Holyfield just went 12 rds with Sultan Ibragimov if say Alexander Povetkin fought Evander next and KO'd him in devastating fashion, We would all take notice, Louis was not as far off as Evander is (remember E.H. was already KO'd by Toney) but Marciano KO'd Joe in a dramatic and impressive way. Same as say Calzage ko's Hopkins in a way that no one has ever done, we would say, yes this guy has stand out talent and some would say Bernard was an old man. Joe Louis is my # 1 HVT ATG of all time but a prime Marciano would have been a Bad style for him even at his best. Louis acomplished more than Marciano in his career but I am not sure he would have beaten Rocky and if he did it would have been his hardest punching and toughest foe ever. Ali was a shell of himself vs Holmes and Berbick and even 6 fight Leon Spinks in there 1st fight. Louis was still a force(not the Brown Bomber) when he fought Marciano, Holmes still had some left when he fought Tyson and that is why Tyson and Marciano still deserve credit for an impressive win
I don't think any HW in history can go into a fight with Marciano planning to knock him out. Not if they want a reasonable chance of winning.
Old or not Moore was the No1 contender when both beat him and had beaten most of the top guys in the division. Therfore he was the man to beat at the time. Marciano had to defend his title against the No1 challenger. Patterson had to beat the No1 to become champion.
I would not go so far as to say it was one of Rocky's greatest fights (can't actually recall anyone saying it was) but I'd say it was one of his greatest fights prior to winning the title, along with the Layne, LaStarza and Vingo fights. Of course, Louis was an old man. He was well past his best, but he was still the great Brown Bomber after all, and was something like 8-0 (or was it 10-0?) on his comeback, beating credible opposition like Lee Savold and Jimmy Bivins. Louis still had that indefinable aura, that greatness...and he was still a player in the division. Make no mistake, Rocky was a little apprehensive about this fight. He commented on how big Louis looked standing opposite him in his corner before the fight, and if you've seen the weigh-in, you'll notice Rocky looking a little nervous, while Joe looks relaxed and calm. It was a good win for Rocky; the fight that finally launched him into the limelight. Sadly for Joe, it was the end of the road, but he was extremely gracious and dignified in defeat.