You have to wind up your punches and kicks for them to hurt. That means your opponent has to kinetically link a series of body parts, and multiply their leverage for maximum impact. Take away those links and there's no power behind the attack. If you hit a golf ball with a golf club, there is a specific point in the club's trajectory that will transmit maximum energy to the ball. Anywhere before, or after that specific point will have less power. Thus the secret to never getting hurt in a fist fight is to position yourself where the opponent's swing has no strength. https://www.youtube.com/watch?v=FjHaeloJvS0 To hit you, your opponent has to see you, he has to judge your distance and strike. Before your opponent can strike his feet must be set, if you keep your opponent from setting his feet his attacks have no power. Thus the ancient wisdom of Tai Chi rings true, the foot must be faster than the hand.