Quote:
Originally Posted by
TyCooN 
Anyone know the science behind this? Boxers can take punishment from combos from hard hitters like Tyson, Hearns, etc, but why do so many people get dropped by one hit out on the streets? Those random people can't hit as hard as guys who get paid to beat people up for a living.

The obvious answer is defensive training and conditioning - there's a big difference between a boxer anticipating a punch and reacting defensively and some Joe Average on the street with zero reflexes who pretty much just stands there and absorbs the full impact of a punch. Ouch.
As to "punch resistance" (which is the measure by which a fighter avoids a KO), there are three factors:
i. Thickness of skull - this is genetic, obviously
ii. Neck strength: A KO is caused by a blow which causes the brain to bounce around (it's suspended in a fluid matrix), bruising the surface. A stronger neck can act literally as a shock absorbed for the head, so that less force is transmitted to the brain (hence less rattling around in the skull).
iii. Dehydration: Boxers dehydrate to hit their weight class, and dehydration reduces the level of fluid in the skull; less fluid - less brain-bounce = fewer KOs. Obviously, dehydration carries its own risk, but it does enhance punch resistance.
DH