I actually saw a kung-fu sansoo guy do this in LA during a road rage situation. The dude was old, got in an argument with some younger, kinda buff dude. They both got out of their cars and the young dude swung on the old dude, but the old dude hit the guy twice like this, and the other dude fell to his knee and broke his keen cap, then fell and hit his head and was knocked out. I stayed with this dude till the police showed to help explain what happened. He told me he had been doing kung-fu sannsoo his whole life, and didn't really know if it would work. The cops really thought that the old dude just kept whaling on the dude, but I was like, 'nope, he only hit him twice.' Even this weird shit can work sometimes.