"Is that definitely for real true? I learnt that from one karate instructor, but others have always said to aim more for the centre of the face, which seems more likely to break a nose and make someone more angry than make them stop. So I've often wondered why we weren't taught to aim for the jaw if it's more likely to be a knockout punch. If it is a knockout, though, I'd be scared of really causing serious injury or worse if when they fall. Which is why fighting should always be an absolute last resort, of course, it's not as predictable or controllable irl as martial arts training can sometimes make out. " Katanita - I was just joshing because LD came over as a fan of quick KO's. But the jaw blow does usually slow-down the action, problem is it's a very small fast moving target which may be difficult to hit (and waste time trying) cleanly. I studied GoJu Ryu for years in what was considered a 'dirty' club and during Kumite there were always injuries, no mats to practice on and even if you learnt zero technique you did learn how to take a beating, which is actually useful because most of us don't fight regularly and it's a real shocker getting whacked, for anybody, including those who've trained to hit but never been hit themselves. Our Sensei emphasised fighting as a last resort, but horrible techniques if you're forced to. Problem with aiming to just cause pain or damage is that although it usually puts most opponents off fighting, there are some nutters (or extremely hard people) that will just grin / continue coming until they're physically disabled to the point they cannot continue. I think you have to be a bit of an ace to pick and choose techniques to delay / injure (but not damage) / destroy an opponent at will depending on the situation, because it all happens so quick when it kicks off - so avoidance is best approach, followed by showstoppers if you're forced to fight, either to buy yourself time to get away / get help or to shut them down. You risk your health trying to use 'reasonable force' on someone who's intent on hurting you !