Could Dempsey do the job or would Biggs be too big and skilled? Remember, Biggs did outbox Lennox Lewis.
Biggs would have landed far more jabs against Dempsey than he did on the evasive Tyson, because as Cus D`Amato once told Ali, Dempsey crouched while pushing his head down and forwards, bringing his head nearer to his opponents lead hand meaning it was harder to eveade the jab because of the short journey that the lead hand had to travel, plus Biggs had a lot more reach than Biggs, so he would have built up a points lead against tge shorter Dempsey maybe leaving Jack needing a KO.
Dempsey by fifth or sixth round kayo. Biggs, outside of the jab, has nothing to hold Dempsey off with. So he suffers the consequences.
Biggs the better boxer and larger. He's also pretty fragile. Dempsey might take his lumps but I think he gets in there with the damage and stops him.