I would bet anything that (if he lived long enough and actually got in to some sort of condition), the great Jack johnson would have stopped Ezzard Charles, Zora Foley, and Marty Marshall (the man who had just beaten and broke Sonny Listons Jaw) as late as 1955, all within 6 weeks or so. Foley and Charles wouldnt last 6 rounds each and I see Marshall being carried to a unanimous points win. 1955 Rules, Referees and conditions. No time machines allowed. Johnson not required to wear the cuffs. Anyone game enough to argue otherwise. I would put anything on it.
Are we talking Jack Johnson as he actually would have being in 1955 ? If it is I'd stake my House on him losing ..and by painful ko .
If we are actually talking a 77 yr old Johnson which I'm sure were not I'd bet the house I would beat him lol
You can't bet on passed away fighters...... How do you propose who the actual winner will be determined if they aren't alive anymore?