Marciano by CLOSE decision. The thing is, I genuinely don't think that Marciano would have a lot of success with Greb early doors. I thik that Greb would spend those rounds staying out of harms way, and, well, frankly, making Rocky look dumb. But Rocky hits so consistantly hard - he's better at this than any great HW, including Frazier, Tyson and Foreman - that he would wear Greb's resistance down. Both men have their plans set in stone by their respective sizes and styles. Where the difference lies is that Greb does not have the tools to change Rocky's plan. The reverse is not true. In short, Greb gets hurt wherever he gets hit. As the fight continues he spends more time on the run and the less time engaging. After a possible early-doors whitewash, Greb starts to drop very close rounds - then he starts to lose rounds big. Rocky locks Greb out down the straight with the Windmill picking up only one round on two cards in the last five, Rocky proving himself the better HW in a decision that is close because of Greb's opening third superiority.
Nobody, I believe under the weight of around 210lb goes the distance with Marciano in a fifteen rounder.... except maybe Frazier.... maybe.
Prime vs. prime, in a series of 10 matches, Marciano would not win them all, but Rocky would win most of these very close fights...in my opinion.
Greb can't and won't put a dent in Rocky's chin. Therefore, Rocky very likely KO's him or wins a decision with Greb on the run for the long hall. Greb has to nearly be perfect to win, and even then in a 15 round bout I don't think he can do it. I'm hardly convinced Greb can take Rocky's punches. Rocky won't be whacking at him cleanly, but he'll get to him eventually and probably hurt Greb and keep Greb on the backpedal. I expect serious arm damage from Greb. Possibly a career altering injurying.
I hate to see what kind of effect Marcianos power would have on a 165lb man who comes right into him. It would not be pretty. Marciano could look like george foreman against 165lb swarmers. This matchup has Frazier-Foreman written all over it. I always thought Greb's style matched up much better against the ATG boxers, than it did vs bigger sluggers which is why he never faced any. For example I think Greb has a much better chance against Ezzard Charles than against Rocky Marciano
How far are you going to take this? Greb would be small fish to Marciano and ends up fried, battered and served.
The longer the bout the better for Rocky ... Greb would give him fits. Rocky would never look worse however against Marciano Greb would be fighting a man who would keep after him without tiring ... eventually the damage would take it's toll ... I like Greb in a ten rounder decision or a twelve but Rocky by decision over 15 ...
I wouldn't pick any boxer in history who is less than 200 pounds to beat Rocky in a 15 rounder, and that includes Greb.
I don't think that Frazier Foreman is a good analogy because Greb was not really a Frazier style swarmer. He dosnt fit neatly into any category but "boxer swarmer" would be the best description. There has been nothing like him in recent years but if you combined certain aspects of the styles of Roy Jones and Joe Calzaghe you might end up with something similar.