I dont think this fight is as clear cut as that. Anytime you put two quick, hard-hitting explosive fighters in the ring together, I'll pick the one who has the most heart, toughness, and willingness( and this goes to Dempsey.) People tend to forget Dempsey had middleweight speed. Other boxers, sports writers etc. could fill a book about Jack's speed. Dempsey was also very explosive. Dont get me wrong, i'm not saying Tyson wasnt quick, because he was. I'm saying so was Dempsey. Tyson may have a very slight lead in speed(?), but Jack had the faster feet.So in the speed department their close in being equal. As far as power, both these guy's could bang and had brutal power in their punches. So, pretty even in the power department also. Now, as far as chins go, Jack's is legendary, described as having a granite chin. In the Firpo bout, Luis had murderous power in his blows. One writer described Firpo as having "George Foreman like" power. And yet Firpo couldnt dent Jacks granite chin. (And this was when the gloves were lighter and thinner!) And Mike Tysons legendary chin-? Jack had the chin to Mike's shots, but did Tyson have the chin to take Jack's ? Also, Mike at times displayed stamina problems, Dempsey did not. So with Jack's better chin and stamina, I see him having the better edge in a slug fest. When Mike was hurt (And Jack WOULD hurt him.) Tyson would slowly start to fall apart at the seams. When Jack was hurt you had a wounded lion ready to maime and kill on your hands. If Mike dropped Jack (And there's a good chance of it.) Dempsey would be back up. I think this could be a big discouragement for Tyson, seeing a man dropped with one of his big shots, and that man (Dempsey) right back up with intensity, ferocity and killer-instinct, and brutally hurting him in return. This could be a mental negative for Tyson. Jack has the advantage in this killer-instinct and huge will to win. So one could as easily say, take away (Or down several notches.) Jack Dempsey's stamina, chin, and do or die attutide and you have Mike Tyson. I'll take Jack by KO in the 8th.