Chuvalo hada great chin and a pretty good punch lacked a bit in skill.
Liston good punch good chin good boxing skills lacked a bit in the the heart department going by the 2 ali fights altho he fought marty marshal with a broke jaw.
Liston stops Chuvalo in a Foreman like performance as the rounds go on big sonny throwing bombs at you your gona go down and stay down at some point i reckon Liston ko 14-17
It should be noted that there is a good chance the Ali fights were fixed, so I don't really base much of his heart off of those.
Foreman was unable to drop Chuvalo with his bombs, he was actually getting a bit arm weary with Chuvalo simply absorbing the punches when the ref stopped it.
At the same time however, that was only in the 4th round, but I don't think Foreman ever would've dropped Chuvalo, he was too slow and too wild to really surprise George with any punches.
Liston would've had a better chance of dropping Chuvalo because he wasn't nearly as wild and he'd have been shoving his jab into George's face the entire night. By the end I think Liston would finally stop Chuvalo in rounds 15-20. He hit too hard and was too good to simply wait until he got tired and then pounce on him, Chuvalo would lose but would've been game up until the end.
