If Joe fights how he usually did, it would be a fun war and he might even score a flash knockdown, but I agree he'd eventually get worn down. Choynski lasts much longer if he fights more cautiously and shows respect. But given Marciano's style, he would get in close and force Choysnki to fight back hard, so it would be bombs away, and Marciano stops him at that game, though his face might look smashed up afterwards. Choynski usually managed to land a few hellacious bombs on everyone he fought.
This comes down to chin ,Rocky had a good one ,Joe's was suspect. Joe Walcott, admittedly a big banger , but 147lbs, had him down 5 times. Sharkey stopped him .Anything they could do, Rocky could do, and most likely quicker. This might end up like the Mathews fight, with the addition of a flash knockdown from Joe.
Choysnski had outstanding hand and foot speed, but he was not the most durable. Some say he was a hard hitter but he fought many guys with average and losing records that he failed to stop. My view is Choysnki might have been one of those sharp hitters who could hurt you with well timed shots but his blows lacked big time concussive force. I think Choynski would do well in the early rounds, but Marciano would take him out later.
This is Rocky's all the way, too big, too strong, too durable and just the better fighter. The most Joe can hope for is a KD but I doubt he'd even get that.
Marciano might get "rocked", but he'd swallow it up and go on to wear down and bust every capillary in Joe's forearms before putting him away with a right to the chin.
Choynski dropped many top fighters. Fitzsimmons, Johnson, Godfrey, McCoy,O Donnell . Jeffries, Fitzsimmons, Corbett ,and Johnson all named him as the hardest hitter they faced. That's good enough testimony to his power for me.
According to Sir Grimswold Foley, a longtime member of the fancy set, who saw every important heavy from Jem Mace through James Broad, Choynski hit with the most clout of any of them. I must to defer to such expertise and pick Choynski by KO in the 4th.
Prime for prime, Rocky wears Joe down. Now, if we're drawing an analogy between Marciano to Jeffries and Johnson when they fought Choyinski, it's certainly possible that, at a comparable point of his career, Marciano might have been bested by Choyinski.
Fall all his 'reverednessness' amongst the peers of his day I do tend to think that Choynski is still an 'olde worldee' fancy dan really whereas for me Rocky Marciano represents for me the pinnacle of for me the best era for fights - after the passing of the old stand up marques of queensbury style and the slower paced long distance fencing matches...and also before the decendance into the lazy overweight money money money days - for me Marciano is a complete fighter and he would've been too much for Choynski - I tend to think Choynski SO impressed his peers because he was so light and skinny yet still hung with guys who were far bigger and at first glance would maybe be expected to trounce him - with the styles of his day I think it may have been a bit different in terms of - if he were facing heavyweights just as big but who fought in a much more aggressive manner and who threw many more punches as they come forward he would have a drastically smaller margin for error (and survival) I think even tho some people view Marciano as crude and limited I think someone like Choynski would've been impressed with Marciano and the advances in his style to a lot of the face first duffers of the post-bare knuckle era - Marciano wouldn't take long to trap Choynski in my book and would break him down in the clinches hurt him and KO him - Choynski may very well fiddle through one or two rounds and maybe brave and keep getting up but something tells me he'd be far too brave for his own good and take far too much
According to testimony from the men who actually fought him . Including 3 heavyweight champions. There is no fight footage of Greb either, most on here would consider him a great fighter though. Your opinion would not be sought I fear.