Bob Foster was an absolute killer at 175, the best ever to fight at that weight. But what if he had managed to scale up to 200 pounds to fight the heavies. How would his fights with Doug Jones, Ernie Terrell, Zora Folley, Frazier, and Ali have been different? Would he have fought Liston, Machen, Wiliams, Chuvalo, Patterson, Ellis, Norton, Shavers, and Lyle as well? How would those fights have turned out?
I am a big fan of Bob at lhw but I don't think it works Foster enjoyed a huge power advantage at 175lb as well as a huge height advantage. Against guys who were as tall or taller, he wouldn't be able to dominate them at range and threaten them with superior power. I don't think bulking up is going to help Fosters chin too much. It may slightly increase his durability. Frazier's ferocious hooks, Norton's hook and right, even Ali's right, and especially Liston's would be too much. These guys hit way harder than any of Bob's 175lb opponents Lyle, Williams and Shavers have too much power. I could see Bob doing a little bit better vs a lighter hitting guy like Jones or being able to decision a tough but limited Chuvalo. At the end of the day, chins have limited. Spinks had a great chin at light-heavy but he couldn't stand up to a two handed hitter in Tyson. Yes, Spinks beat Cooney but Cooney was very limited and unmotivated. Bob, while a great 175 pounder, was not a slick boxer who could outbox heavies. Bob's game was keeping his opponents at range with his tall frame and jab and catching them with devastating rights and left hooks. Those power advantages disappear at heavyweight. H2H I favor Bob over most of the ATG light-heavyweights. But heavyweights are tough.
I agree, it might not help his chin, but his power would be on closer levels with the heavies, so doesn't that mean they would be more likely to get knocked out? I don't think a beefed-up Bob Foster would beat a lot of those guys, but I don't think the losses to Frazier or Ali would be half as embarassing.
I agreed with most of your matchup choices. But I think a big Foster could knock out Folley and decision Machen. What about 200-pound Foster vs. Norton and Ellis. They were great fighters, but could only eat so many power shots.