Well I believe that's a mistake. Dempsey's head movement, isn't textbook and it some him leaving his head being used for target practise. We can't see many of the bouts he got hit allot in but we know Tunney, Carpentier, Gibbon and even Firpo hit him without his head movement being effective. Dempsey's lasting talents are his use of angles at close to mid range and the ability to turn over punches effectively at those ranges with powerful leverage. There an argument that ability holds up as elite today but certain not his headmovement and I don't believe it was very good for his era
Edit, multiple trainers teached the Dempsey roll wrong. The Dempsey roll is really effective if you use it well. I agree
I mean, it's just a variation of the bob and weave. Of course it works, whether it's better than the more traditional bob and weave is what's up for debate but I think an underrated benefit of the Dempsey Roll (if we're talking about the figure of 8 thing he did with his head) is that you don't have to do it at full speed or by reacting to opponents. You can do it quite slightly, in the same way you'll see Tyson slip slightly off line on both sides when pressuring. It's not enough to actually avoid a punch, but it's much easier to exaggerate that movement when you see a punch coming than if you were just there with your head still. An object in motion stays in motion and whatnot.
It works especially well if you learn how to punch as you roll. If somebody took the time to look up what the Dempsey triples were- and there were two specific sequences- and learned how to do them on the heavy bag, you would attract attention in just about any gym. If you pulled them off in sparring, you would immediately become the stud pony in that pasture.
You stand infront of an opponent doing this ,you'll get knocked the f out. while he is standing there doing his break dance, you just hit him in the temples whenever his momentum swings him towards you. Or just clinch and it stops him and repeat that til he gets tired. Or you just get to the side and now he can't do much. IMO this just looks so stupid.
You do understand that is a cartoon? And that it has zero relation to what the Dempsey roll actually involved?
It work for Dempsey. He also fought with smaller gloves, so you got to think of the styles of the era.