Being bothered but staying on your feet and recovering is hardly the sign of a glass chin when you get hit by a fully fledged HW is it? Watch that video i posted.... Tua lands flush with several left hooks and they don't faze him. Then watch that straight right Holyfield puts square on his chin that doesn't faze him..... the right straight that landed on the point of the chin from Vitali and he was still standing... the guy didn't have an iron chin but he had a good chin. Everyone would agree Ali had a good chin and he got dropped by Henry Cooper