Wong Shun-leung said that when you punch the head the brain hits the side of the skull. If the brain is against the side of the skull and a second hit follows, then damage and a knockout results because there is no cushioning possible. This is why Wing Chun has its rapid fire punches instead of the pull back approach.
martial artist
Wong Shun-leung (黃淳樑 1935 – 1997) was considered by many to be "the most famous fighter of the Wing Chun clan in the early 1950's". Since his reputation was world-wide as a Wing Chun master and a sought after seminar speaker, Wong had been interviewed many times. Based on information gathered during his various interviews, Wong had expressed his profound knowledge of various aspects of fighting. Today's martial artists can obviously become better fighters if they can fully understand and absorb Wong's profound knowledge of fighting. Following is a small collection of his profound opinions regarding various fighting principles and combat concepts.
From: Wikiquote (CC BY-SA 4.0)
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The late Sifu Wong Shun-leung, of “Hong Kong” wing chun fame, in his seminars around the world over the years, liked to make a comparison with the modern combat sport of Western boxing, which he observed had changed quite dramatically over just the last sixty or so years, from the crouching-like postures of boxers like Joe Louis in the 30s and 40s, to the flashy footwork of the likes of Muhammad Ali in the 60s and 70s, through to the more upright and flat-footed approach of recent champions such as Mike Tyson.
I am now teaching Wing Chun and am in no position to criticise other Gung-fu systems. I would like to say, however, that many styles ask men to imitate animal positions. Humans don't have the ability to imitate some positions. For example, some animals can leap around from here to there quite easily because they have long tails to help them maintain balance. We humans don't have such a tail to aid us, and so some techniques may not be natural. Therefore, when someone asks me what animal style Wing Chun is, I will always say that it is 'human style'. We use the weapons which nature has given us to the best of our ability.
I think the kicks in Wing Chun are enough. It´s much easier to use your hands than to use your feet. Your hand is able to reach your opponent long before your foot. Why take the long way to attack (circle), when there is a much more direct method of attack? If you are using your hands, then your opponent can´t see a kick coming if you have to use it. When you teach Kung Fu, you can fool a lot of people, but not yourself. You can make like a movie and do many complicated movements and kicks, but you only fool yourself as to whether that would work in a real situation of life and death.