We know that there are three families of wing chun; the tan, bong, and fook. In short these are techniques that use the radial edge, the ulnar edge, and the middle part of the hand / forearm, respectively. Knowing this, techniques can be classified into one of these families; e.g. gaan sao being part of the bong family or jut sao part of the fook family. These are also known as the three seeds of wing chun.
To expand on this, when I think of "seeds" I think of a starting point by which something grows from. That said, there are a lot of things that can be learnt from a single movement, even though it may not be explicitely expressed as such. I thought that this would be a good format by which to expand on the various indirect things that we've all learned in our studies of wing chun.
Some simple examples from CK and BJ:
The 3 bong sao movements done with steps, can be interpreted as an overhand punch when moving in. Same motion, but with the hand in the form of a fist. Basically a pak - da using the bong sao's motion.
A step forward doubles as a wang gurk as you drive the leg into the knee and down the shin of the opponent while moving in.
The double bong can be used as a defense against a bear hug from behind, using the sweeping legs of biu jee combined with the waist turning can use fak sao or wang jeung to the upper body to take down the opponent (you can use a soo gurk sweep at the same time for good measure).
Less explicit example:
When you lap sao say with the right hand, you can use the sweeping step from BJ with the right leg to make yourself sideward while at the same time using a forceful waist turn clockwise (to coordinate the lap, step, and turn) into a quick arm break using the body as the fulcrum on his elbow.
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Anyone have any other not so obvious applications using wing chun "seeds"?