Originally Posted by Squirrelfighter
By tuking your chin/lifting your hands to jawline level you minimize and in most respects nullify any kinetic trauma to nerves within/connected to the jaw.
Just to add to that if your chin is tucked and you are in the correct stance then when you throw a strike your chin is protected from hooks by your shoulder until you hand returns to its original position.
"I fear no man, but Jim Harrison and Mike Stone are the two last men that I would wish to meet in an alley fight. Jim Harrison's fighting style is not flamboyant or spectacular, it's just simple and deadly!" - Bruce Lee