How can you rank fighters you didn't see on tape?

If Floyd Mayweather and GGG, had a closed door fight. No cameras, no recordings. With just a few press, and a few rich viewers. They both had full training camps, and then fought a proper 12 round contest. And Mayweather wins a landslide decision, and all the press talk about how easilly he won, and how brilliant he was, would that not inform your opinions of GGG and Mayweather?

 

The thing is we've got ample footage of both GGG and Mayweather before the bout, and ample footage of their opponents. Hell, we have amateur footage as well.
It's easier to judge variables when we already have an accurate pre conceived notion based on extensive footage.

Some older fighters just don't have that, great as they are.

 

You just rank them higher than everyone.

 

By hanging on to everything written on a fighters ability that suits your agenda and shunning those that oppose him......

 

I wonder how many minutes of footage is necessary to rank a fighter.
Can we make a proper judgement based on one filmed fight or a few minutes ?

 

You can't.

Too many people rate part-time milkmen from the 1910s as all-time greats because Bert Sugar fanboy'd over them.

 

Which part-time milkman is rated as an ATG ?

 

No because we would have never seen Mayweather or Golovkin on camera before.

 

I knew Sugar Ray Robinson was great before I saw him on film.

 

Again, these are "easy cases." The same for someone like Greb. But what about the marginal cases? And aren't these marginal cases the ones that generate real debate?

Heck, even the most stupid young fans concede Robinson was great.