Been done before I'm sure. Carnera was 6'5", and around 250 when prime. Marciano was 5'10", 185. Carnera could take a pretty good punch and had decent power. Marciano never lost and had the highest KO percentage ever.. Who wins?
Bad style match up for Rocky. Carnera has a huge reach advantage, then there is the weight and we all know how Rocky "never fought a young super heavyweight" ....
Give them ten rounds and 10oz rubber/ foam filled gloves like they use now rather than the 6oz horse hair bag gloves they used then and its even tougher for guys like Rocky and Louis. Giants rule!
I think that we are ultimately going to come down on the side of Marciano here, but it requires a few assumptions. Not that the opposite position doesn't.
6'5" 250 lbs versus 5'10" 185 lbs That is a 10% taller and 35% heavier man Those are ridiculously horrible circumstances for the smaller man Even if we took the incomparably faster of hand and foot Mike Tyson (instead of the slower and tyrannosaurus-armed Marciano) but then stripped away that much weight he would be blown out by almost any decent 6'5" 250lber. Without enough weight you have nothing to absorb what comes back at you, can't bump or push your opponent, can't maintain your own balance if brushed by the substantively larger man, and don't bring enough heat in a single shot to hurt someone that large when you inevitably must take the risk of getting into range to attack. Obviously, the contention has to be that Marciano is the greatest 5'10 185 that ever lived and Carnera is the worst 6'5" 250 fighter that ever entered a ring. ------------ If we reduce it to middleweights and keep the same differential (ratio) .... it would be the same as facing a bantamweight It would be a 5'10" 160 lber facing off with a 5'4" 118 lber. At 5'4" 118 you may be lightning quick but you aren't Manny Pacquiao either. The lightning quick Manny Pacquiao wielding probable PED accentuated power (when he moved up to junior welterweight) is 5'6"ish. Any historians have an awesome 5'4" 118 candidate to face off at middleweight? Keep in mind every inch and pound matters .. can't go up in height OR weight as you surpass the metric for Marciano vs Carnera. I know some like the "I remember when Tiny Tim entered the bar and beat up Paul Bunyan" stories but the exception makes the rule .. these things almost never happen unless you have a sling shot and he's standing with the sun in his eyes ....
I don't think it's an easy fight for Marciano but I think he would win. Carnera is better than any of the few large heavies that Marciano fought but that is kind of like being the smartest dunce in the room. If Marciano tries to maul Carnera that could drain him quickly. He would need to get off his shots while separated. And I think he would. Rocky knew what he did best and would know this even against a different sort of opponent.
How would Kovalev (188 lbs 6'0" (not 5'10")) do against Wach (249 lbs 6'7.5" (not 6'5"))? Would he win easily? Would he wear down Wach through attrition? Would "getting off his shots" lead him to victory? Essentially the same size differential (height/weight/length) as Marciano vs Carnera [Kovalev entered the ring at 188 lbs versus Hopkins]
If Carnera was any sort of a puncher and had a durable chin I think your argument would be valid but he wasn't, so I have to expect Rocky to gradually dominate him . Carnera might just make it to the end though.
Really short, slow, and with no reach, seems the worst aggregate hand to have in facing a comparative giant. Not the optimal nor an advantageous toolset for such a job. It would be a very difficult task. --- How about a bantamweight to fight and defeat a middleweight? I was looking for someone pretty crummy .. like a Lajuan Simon or someone but then saw he is listed at 6'1". [edit: maybe Morrade Hakkar would fit the bill] Want a 5'10" 160 versus 5'4" 118 ... if the proportions are the same as at heavyweight between a superheavyweight and Marciano then surely someone has a bantamweight they believe was capable of beating a middleweight. It is entirely different if Marciano came into the ring at 220 lbs than at 185. Toney - while similarly short - took heavy shots from heavyweights but he had the girth and size and resistance that comes from weight. Without the weight (and with no speed at all to be elusive or stay on one's bike), these size differentials are too much. Haye versus Wlad, Cunningham versus Fury, Jones vs Ruiz, or any number of other examples when small heavyweights face super heavyweights are not examples of little guys strategically trying to tire out big ones by running but rather guys giving away too much weight and knowing they can't remain stationary, trade punches, and survive. They physically recognize they must limit the punishment they take and make their larger opponent miss to stay in the fight and score points. Marciano is not going to be able to get in and out or remain at distance with his reach, wheels, and attributes. 185 is awfully small (light) to face 250. With his attributes he will have to stand and trade with an immensely bigger man. [Which is why - even in ignoring styles and other attributes - I asked how one would envision Kovalev (at 188 lbs) approaching the problem of Wach (at 249 lbs). How does he make that a winnable fight?] If it wasn't for some of Carnera's other losses (and I haven't seen them all), it is near impossible to see or imagine Marciano having the right tools. Louis was much taller, comparatively quicker, more athletic, and brought a much different complement of tools to the fight in '35. It still took a lot of awfully nice precision work to do the job.
Marciano had the pace and the power. He wins. But it is an ugly, woefully awful fight to watch. Even so, most will agree Rocky wins. I think Carnera had a decent chin. At worst it was as good as wlads. Only Joe Louis and Baer beat Primo by KO in his prime and they wore tiny gloves.
Because of his speed and dynamic style I see Dempsey ruining Carnera.Marciano a plodding, grinder compared to Jack I agree has a much stiffer task in front of him.