He'd beat anybody who existed before his time and some of his successors too (Johanson, Patterson etc.) Just match him with his own size and type, old-timers or smaller modern guys and he will pull out a W eventually.
I think Louis - Liston is a good fight. Louis about the same size as Liston, Louis was taller but Liston was around 10 lbs heavier in their respective primes. Louis was on the same level as a puncher and was equally skilled. And I don't see Louis being intimdated by Liston and was less likely to quit on his stool. The X-factor here is how well Louis' chin holds up. I don't know that Louis ever faced a puncher like Liston (with the possible exception of Max Baer - but Max was on the way out when that fight took place) and Liston was twice able to handle the best shots of Cleveland Williams and score early round KOs. If I had a gun to my head, I would pick Liston. But if Louis can survive the early rounds and still be banging Liston with hard shots in the middle rounds, I wonder if Liston's bully mentality would betray him...
Louis is the better fighter, but stylewise you have to go with Liston by early to mid KO. If teh fight goes past 7 rounds I'd pick Louis by KO....but it wont.
I have Joe Louis here over Sonny as the "Bully" stuff wouldn't work here with the Brown Bomber. Joe would have taken the fight inside and broken Sonny down to the body, just looking at all of that girth to punch at would have made a killer like Louis salivate at as he would have hit Liston with hand grenades in there. Louis KO 6.
