Marciano was very inexperienced at the time of the first LaStarza fight. He never put on boxing gloves until he was well into his 20s, had a very brief amateur career, had fought mainly weak opposition in the pros, and most of his fights had ended in the first two rounds. He was still a raw work in progress at that stage of his career. In addition, he had just nearly killed a man in his last fight, and according to many accounts had strongly considered retiring as a result, which quite likely had an effect on his psyche. In fact, observer accounts of the fight do describe Marciano as having been unusually passive and tentative in the early rounds.
I would highly favor Marciano over a 60 year old Holmes. And Marciano vs Holmes prime for prime could go either way.
I'd take Holmes over Marciano. He's got the height and reach over Marciano, and his jab would dictate the fight. While Holmes doesn't have awesome power in his right hand, he could drop Marciano down the stretch. The biggest threat to Holmes would be when he tires a little bit during the late rounds, and has to stand and fight. But he proved his toughness so many times against Norton, Cooney, Shavers, Snipes, and Witherspoon among others. Marciano loaded up with his punches, usually wide hooks, and they are not going to hit Holmes regularly enough to have him in serious trouble. Holmes on points.
I don't quite see Holmes as the stylistic nightmare that many good posters out here see (JT, et al.). Holmes was a rythym fighter like his sytlistic blueprint was. (M.A. -the Master of the Arts, Muhammad Ali) I also think that he developed his own style with based on his different assets. I think Frazier would beat him. I think Liston would beat him (and went into details on another thread). I think Marciano, given a little luck, had a damn good chance. Tyson too. All four of that crop have characteristics that would be problematic for Holmes and that would exploit his weaknesses. Particularly Tyson.
I'd stop far short of nightmare, i actually said "He matches up well vs near anyone." I do believe that in that he could IMO fight well vs a variety of fighters. I think his style would be very awkward for Ali, and holds him in good stead vs most anyone else style wise. Frazier would be tough for Holmes as i agreed. Marciano is also tough, durable, superbly conditioned and has that great right hand Holmes was often found leaky against. Fully understand these picks, i've always been open and respectful to contrary opinions regarding Holmes, he did after all have a lot of trouble vs some pretty average (Compred to greats) fighters at times. He could be both found and put down at times, but did get thru this every time. There'in lay the eternal barometer per Holmes, could he rise to the occasion and survive rocky moments against much much better fighters. I think he mostly could, but would never enter heavy confident debate vs the opposing view. It has it's points, and a lot of angles.
JT, I just scrolled back and saw that Janitor used the term "stylistic nightmare" and Nick Hudson had him at least 50/50 against anyone. Sorry, if I misquoted you. I agree that Larry was great and would be a live one for anyone, due to his talent, skill, and especially his will. That man's arrogance translated well in the ring! He could have earned a place among the "indomitables" on that other thread. I'll never understand how he got up from that Shaver's overhand. I thought he got shot by a terrorist. I would however, go so far as to proclaim Tyson and Frazier as stylistic nightmares for him. I also think, as you know that Liston was simply too strong and had skills that compared well with Holmes.
From my recolection Cooney's wide left hooks to the body, when they landed, appeared to hurt Larry. And those were just one big one every couple of rounds, sometimes a bit more often. Frazier would put a serious body attack on Holmes, and I think it would most defenitelly take it's toll. Didn't Frazier break Larry's rib in sparring?
I'm comfortably taking Holmes by UD in a 12 round fight. In a 15 round fight I wouldn't take Holmes with such confidence, because although he finished strongly in most fights, he did look extremely winded towards the end of them. I think Marciano would be that much stronger, which would give him a much greater chance.