How much punching pressure to knock someone out?

The fact is, that everyone has a different amount of pressure that will shut their lights off, generally speaking an average punch has about 650-800lbs ( Professionals swing at about 900 to 950lbs...kicks in the 1100-1400lbs range) of pressure distributed within the size of the individuals knuckles. 600LBS to anywhere in the skull will cause the brain to whip-lash inside the cavity causing swelling...which we know as a concussion. The body needs electrical signals from the brain...if communication gets cut off for a split second, our bodies exhaust all resources and shut down like an emergency kill switch in order not to keep sending failed signals from the brain. The jaw line and temples are especially vulnerable for knockouts. But keep in mind knock out factors: heart rate (tired individuals get knocked out more easily) Size (skull, body mass index, Fat content etc.) No human on earth sails above these laws of science...i hope my answer was informative.