I agree Thia. I was just going on the theory that if you do know how to throw a solid roundhouse to the head that is not seen coming because of the stunning blow it can be a affective way of ending a fight. And if you are refering to sombody being able to open up with a high kick then I have seen few who can consistently land a kick chest high or above at the very beginning of a fight against a trained opponent. Not saying it is impossible by any means but just not something I would ever do as a opening manuever. Everyone is different in the way they fight. Some faster than others , some stronger. And going back to a roundhouse to the head not being able to finish the fight if landed by a proficient practitioner , It may not knock the person out but it will in most cases make it to where you can without much effort get away if need be . In turn I mean the fight will be over if you want it to be.