No definitive way, but Liston was scared of Ali. It's pretty well documented that Liston believed Ali was truly crazy and that scared him.

When he was younger he would have had more of a chance but I think he was beat just as much on the mental front as he was in the ring. Also, Ali was the first guy Liston ever faced that was bigger then him.

Liston as a young fighter was an animal though. Loaded up with every single one of his shots and had one of the heaviest jabs in boxing history. Not great speed, but a ton of power. Not sure if that power was all there when he fought Ali. I'm not sure of the Liston timeline before Ali and if I've seen those fights, maybe that would clue me in a bit more.

But I would take Ali over Liston. Liston would have a better chance, and I don't think he would be walking through any Liston blows but I just think he was a class above. Factor in the mental edge and I'm not sure I could foresee Liston winning.