Boxers know that the chin is the target when knocking out opponents. That's the point of the TS.
The chin is the "sweet spot" and that's where the term "glass chin" or "glass jaw" came from.
quote: "When a fighter talks of hitting someone "right on the button," he is most likely referring to a chin shot, a punch delivered directly to the lowest point of the jaw. In boxing, this is known as the "sweet spot." The reason that a punch to the chin can be so effective in rendering your opponent unconscious is due to the laws of physics. The bones lining the lower sides of your jaw are very conducive to vibration. When a punch lands directly to a person's chin, the energy transmitted travels through the underside of his mouth, up the rear jaw-bone and into the brainhttp://www.livestrong.com/article/13772 ... ch-boxing/
It's for this reason I wanted to point this out the next day after the fight when this "glass chin" threads started. I saw Amir Khan getting hit in the neck (or the nape) and I felt he cannot recover from that.
I know from experience that a blow to that area can paralyze and even kill a person. Karate experts (I'm not. Just a street brawler in my youth) know this and its a prime target with a single chop to paralyze their opponent.
But if guys here say Amir Khan has "glass chin" to mean he easly gets KOed, then no problem with that although the definitions refer particularly to the jaw, figuratively or not. I agree with the TS on what he saw, Khan was hit on the neck below the ear and never recovered till the stoppage.
Keep watching the video.
Look at his mouth.