Marciano didn't "nurse" his '0' losses

[Master]

Being undefeated is no reason to be regarded as a great fighter just look at Sven Ottke for an example of that reasoning.

The fact that old Walcott an dropped and gave Rocky so much trouble in their first fight is not a sign of greatness but coming back from the jaws of defeat was.

Walcott was HW champion at the time, he had a late prime. When he fought Rocky, he was younger than Wladimir Klitschko, and younger than Vitali was for his last several dominating performances.

You know better diets and training regime means boxers today box longer. Walcotts age is equivalent to 50 year old by today's standard.