Well, has anyone who isn't a decent puncher had him in serious trouble? Being hurt by decent punchers doesn't indicate glass, it just indicates that someone doesn't have a very strong chin. It's not granite or glass; it isn't that binary
I would say HEART > CHIN example Ruiz v Joshua 1 - would fury have ever quit in the same situation wilder v fury - would Joshua ever been in a position to continue after the 12th round knockdown
There are many grades of mandibular fragility, I don't disagree. But the bottom line on Williams is that he just doesn't seem to take a very good punch, which has - and will continue - to impact his ability to compete at the highest level.
I agree with that but to my mind not taking a *good* punch ins't indicative of glass, it's just showing someone doesn't have solid whiskers. Glass for me is when guys who aren't hitters are putting you down or wobbling you