David LaVerne, one of my partners in crime, suggested this rule to help us understand why we have to "adjust" the kata moves in order to interpret them.
- The Shadow-Boxing Principle: A one-person kata is like a two-sided triangle.
This means that a one-person kata is always incomplete. It doesn't contain all the information it should.
When we watch a two-person drill, the combat nature of the techniques is plain to see. If we remove one person from the drill, however, we don't just lose information. Something unexpected happens. The remaining performer inevitably begins to retime and refocus the kata in order to put on a more impressive solo performance. This is the "Shadow-Boxing" effect. One-person performances are inevitably warped away from the original technique. A few generations of shadow-boxing can warp a kata pretty badly.
As a simple example, take steps 4-5 of heian shodan. (This would be section 8.3.3 of Shotokan's Secret, Expanded Edition.) In step 4, Shotokan performers yank their hand back "to break a wrist grip." Then in step 5 they complete a circular motion in a hammerfist. The usual explanation is that the opponent grabbed your wrist, so you yanked your hand free and then struck down on the top of his forearm. This always seems kind of weak to me.
Karate jutsu artists know that step 4 has to be performed gently and gracefully in order to apply a wrist lock that sets up a neck break in step 5 (the hammerfist). If you yank hard to "break the grip," you lose the lethal followup.
The point is that some moves, like wristlocks, are most deadly when graceful. Unfortunately, Shotokan teachers have turned those kata moves into hard-focus power exhibitions, which will not work as originally intended. The "Shadow-boxing principle" says that we will have to soften and retime many of the kata gestures in order to fit jujutsu applications to them.
