What qualities allowed these individuals to rise up above the rest and do what so many thousands wanted to do but could not. What do these greats have that the 1000's of other boxers didnt have?
Genetics for the sport that they chose to be in, and mental strength. But IMO Mainly their genetics Thats about as simple as it can be put.
I'd reverse the order, but I agree with them. Incredible mental discipline is the single most important attribute to excel in any sport. Getting up early every morning, running mile after mile, and spending thousands of hours in the gym, day after day, is a harder GRIND then any job. It hurts, there isn't a ton of money in the beginning, and it prevents youthful enjoyment of life in traditional ways. Anybody who discounts the importance of what is between the ears hasn't done it for a living. After that, it is the fact that they are born just that much more gifted then the other rare fighters with their supreme level of focus.
Thanks as always mate. In case you didnt realize people this is an absolutely epic answer to the question!
The mental durability even translates to physical; These greats all have the guts and courage and focus to hold up under pain and heavy fire. Ali-Foreman, Lewis-Klitschko(For both of them), Marciano-Charles/Moore, Louis-Schmeling I,Braddock,Walcott(both) When the going gets tough, the tough get going, and the great take off.
Personaly, I would not mention Vitally Klitschko in the same sentence as the other fighters on your list.