I would say that it was very comprehensively tested. You find out how good a fighters chin is, when they started fighting rated opposition. Not just big punchers, but also fast fighters, fighters with good delivery systems, and fighters who are mounting a serious attempt at winning. Louis fought every size and style of opponent imaginable, and nearly half of is fights were against top ten ranked opposition. I think that what we have seen, is what we are going to get.
About a 7. He had above average recovery ability much like Ali and Robinson. He could be hurt an dropped from time to time usually got through those moments.
I say an 8.5 .. Schmeling was a serious puncher and hit him flush dozens of times before taking him out .. Galento hit him w a bomb and he came right back. Buddy Baer was a big puncher and Joe took it and came back .. Walcott could hit and Joe came back .. he also got stronger as he got older .. look at Ali .. decked by Banks, badly rocked by Jones, pretty much out vs Cooper .. as an older fighter he got tougher too ..
From the old Ring Magazines I own from the 50s and 60s pundits often characterized Louis' chin as being 'soft' or 'chinny'. To me that seems unkind. If you're slinging leather with bombers like Galento and Schmeling, you're going to wind up on the canvas now and then. I would say his chin ranks similarly to Chico Corrales. He was vulnerable to getting dropped, but he never got flatlined out of no where. You don't need to be Billy Graham to have a good chin.
I think his chin along with his slow feet are his biggest weaknesses when considering h2h ability. Somewhere between 6-7, average for a world class fighter. I don't think he could take a flush shot from punchers like Morrison, Ruddock...
This is good from his perspective, because you seem to chronically under rate both. There are punchers like Morrison and Ruddock in every era. They are really nothing special.
The numerous rights Max hitting Joe with, ballooned Joe L's jaw up similar to Ali's jaw when Frazier hit Ali with all those powerful left hooks over 15 rounds.
Definatley 10. I would say most of his knock downs were slips. Considering that he took shots from the hardest punchers like Baer and Galento I would assume it was easier to cheat back then with loaded gloves...Louis didn't care. He took shots from those small gloves, you have to compare the padding of eras ...the proof is in the padding not pudding in this case.
I don't think that it is to be honest. It clearly took a sustained beating to stop him. His chin was not the best among lineal champions, but nobody is going to beat him on power alone. Forget Ruddock and Morison, it would be a better hope to send in Chris Byrd!