Your main goal in a real encounter? Stay standing! The reason that Wing Chun kung fu was invented is survival. Self-defense is a right of every human being. In ancient times, there were tough-man contests, but nothing terribly organized. They were no rules or few rules.
Wing Chun kung fu developed separately from those regular contests. It was kept in a narrow family line for generations. Over time, it spread for sure but nothing like the fancier methods or the ring-fighting, tough-man contest methods.
The idea in the Wing Chun families was to pass down something that would be useful for their descendants against faster, more skilled, attackers. It became critical that a defender remain standing. Once on the ground, an aggressive, larger, attacker will have a huge advantage if that happens. Odds of survival go down significantly.
At the heart of this art was the fast-moving footwork. In order to avoid clashing with the force of a stronger attacker, one’s feet must move quickly, lightly, but be firm when striking a blow! To make it work, the foundation footwork must be half of your homework! Some branches of this art that evolved from the Yip Man root have lost some of this important emphasis. More about the history and the how and why these things happen is in the book Roots and Branches of Wing Tsun by Grandmaster Leung Ting. Fascinating reading!
-Sifu Keith Sonnenberg