Fifteen? Dempsey is already home & showered in the hour a 15-rounder would take. This would get really ugly, really fast, with Dempsey’s speed of assault. I have it over in the first, but no chance it goes past three or four.
In all seriousness, I believe that boxing does indeed evolve, techniques and set ups get discovered, defence, ways to make your attacks less predictable. Yes guys like Shavers and Cooney beat him in 1 round, but they have much better technique than Dempsey, are bigger and he more ways of setting up punches.
Ugly? Hardly. Norton wouldn't take any kind of sustained damage or vicious beating. Dempsey will love tap him with a left after coming out of a crouch and Norton will enter the 3rd stage of REM for a couple of minutes. It will look peaceful, in a way.
It depends on if he's fighting the 1919 Dempsey or the 1923 or so Dempsey. The 1919 Dempsey, the hungry animal, it could get really ugly, he might pick Kenny up and hit him again just to make sure.
This just got me thinking about Norton going down from a grazing punch, being unconscious for like 3 seconds, opening his eyes and hearing the referee yell the count, then he would prepare himself to get up only to look to his side and see Dempsey right above him, smiling at him. I then imagine Norton closing his eyes and making a snoring sound for the rest of the count.
Norton. Too much athlete. Too much defense. Too much jab. Too much man. This isn't some stiff rodeo rider punching bag. KO8