What did Joe Frazier have that Rocky Marciano didn't?

[AdamGB]

Joe Lewis was not a credible opponent? he was only 37 years old. George Foreman until he was 49. Larry Holmes for until he was 47. The Klitschkos are in their mid forties.please. Charles was not a credible opponent what are you smoking. Archie Moore and Roland la starza and don cockell were not credible opponents? Jersey Joe Walcott was not hit a credible opponent? Harry kid Matthews was not a credible opponent?

'Credible'? Yes
At their peak or even close? No
Shot? Often

Are you telling me that because Big George fought till 47 that it some how makes it the norm?

Heavyweights fight till older now, but it's not the 1940s anymore.