I have three thoughts: 1) Greb had a huge edge in that Tyson and his team cannot study him due to having no film available. By the time they get a handle on Greb's style, he is too far ahead on points for Tyson to catch up. 2) Greb is a greatesr fighter than Buster Douglas, and Buster beat Tyson. Again, advantage Greb. 3) If they are fighing oldschool rules with newspaper judges, all Harry has to do is last the distance. Newspapers loved Greb, so he takes a newspaper decision. I'm having trouble finding any way for Tyson to win.
Bad style match up fpr Tyson Tyson always had trouble with smaller guys, he never could get used to punching downward. Tyson would have his moments, but if he hit Greb more than one punch at a time, Greb would get angry. You would not like Greb when he gets angry. The madder you mae him the stronger he gets. Bad night for Tyson, Greb by KO around rd 8-9.
Let's put it like this. Tyson was an animal, but he was only a 6 rd fighter. Greb could fight all day and would tie up , hold and do what it takes to survive. Despite the difference in size, it's not unrealistic for Greb to win by KO in 18.