I don't think Bivol really has the firepower to keep Marciano off of him for the whole fight. I do think he has the stamina to compete all the way down the line but is it enough? Bivol would have to try build a big lead early and use his great footwork to stay away for the second half of the fight. I think he may have an outside chance of pulling off a points win.
Won't comment until Bivol's chin is tested against quality punchers. If he has an iron chin, there's a high probability outboxes Rocky. If he doesn't, Rocky likely runs through him in about 8-10 rounds. Even then, we won't know until Bivol faces someone like Beterbiev.
Bivol has a good chin. He's been caught by big hitters before and came out ok. Biggest punch landed on him was by Smith which was a clean shot and it wobbled him, but in the end he was fine. Smith is probably one of the top 3 hitters at the weight. Of course, I'd argue Marciano hits harder and probably harder than Beterbiev too.
Marciano would do what Canelo tried ,target the arms to bring down the guard,and nullify the jab,he would be too much for Bivol,imo
His skin was extremely fragile. Bivol tearing his face open is far more likely to stop the fight than "bicep bombs".