i agree with what you say here but its possible he means in a combination of forces like if the guys throwing a hook so hard that he turns his head with it as your throwing a hook directly into where hes turning his head that would still be head on. or like in a right cross counter would also be head on. just as the opposite where if you roll with a punch its 2 opposite forces and the impact is no where near as bad....though the greater your velocity the harder it is for you opponet to roll with the punches. like ali vrs foreman with ali rolling with everything, foreman heavy handed but not a fast air cutting puncher like shavers.
Okay, so it is the weight of the head that is important. I guess we need then to look to Fitz KO of Corbett where he hit the body and not the head. That gives him a mass which is so great, that if we assume the acceleration to be the same as or at least half as great as any head shot we have seen, Fitz will have issued an awful lot more power than any of those super heavys, who can only seem to KO the head. By the way, you seem to have an awesome knowledge on this subject.
well fitz hit the solar plexus, a nerve center nearly as bad as getting hit on the button and a bit worse then a liver punch causing your diapharm to pretty much give up and stop you from doing anything including breathing for a few seconds. plus if corbett was fresh i doubt it would of had the same effect. you really cant say how hard he hit but as corbett didnt fall backwards one can saay that there was little displacement so the punch had to of had great velocity and great impact force. and thanks, ive been trying to figure out the physics of a punch on and off for a while now and really im still not sure if im correct so maybe tomorrow ill ask at some physic forum.