I think there is a little more to it than Khan merely having no chin.
He seems to throw a load of punches and when he misses he leaves himself right in the slot for a huge counter .. that can be worked on big time.
He can take shots, the Maidana fight proved that to some extent, but in that fight he was more reluctant to throw shed load of punches and risk being countered by someone that he believed was heavy handed.
I just think he thinks he can take shots against supposedly lesser punchers and therefore takes risks ... the problem is then hes caught flush when hes in no position to absorb such punches.
Cannot believe im slightly defending Khan here ...Sc00by is going to jump all over me now.