Re: Could Marciano have feasibly went 77-0 in place of Dempsey?
It's impossible to know how good some of Dempsey's early opponents were. Even in regards to accurate record-keeping and compiling record books, things had come a long way from 1914 to 1949.
We don't even know when Dempsey actually started fighting professionally. Maybe 1911, maybe later, maybe earlier. It's impossible to know much at all about his opponents, or how many fights Dempsey had.
Dempsey started out away from the cities where there were men keeping busy reporting and recording prize-fighting.
The level of Marciano's opponents is far more easily established.