afulldeck wrote:So what makes a variation a variation?
Wow. Superb question.
Now to try an answer? Another "Wow"....Canonical 'text book' waza have a certain basic principle
in their action that must be executed to achieve that given principle. Oh dear....The smart ass answer is a hon waza becomes a henka waza when it varies from the hon version to the degree it becomes another technique. That is of zero help though. Phewwwww.
Most judo we achieve is henka. Hon waza are a theory, A base from which to build and understand the principle of a given throw.
When is harai goshi, Ogoshi with a sweep? When is harai goshi, ashi guruma? The all pervading principle of harai goshi is to sweep the loin of uke from under him. The leg does NOT sweep ukes legs away! The action leg is a guide to build impetus and direction for tori's HIP, it is the hip that throws uke not the leg.
Size and body type not to mention psychological character will make all our judo waza vary to a degree, its the lore of biophysics. Non of us are built the same and no too actions can be replicated to the absolute identical action twice.
Grip in most waza can vary. The idea is not to measure grips by the millimetre but guage the efficiency in how a given grip may best execute the required principle of a given technique.
Tomeo nage is not sumi gaeshi. Perform them for a novice and he will not be able to see the difference. In reality both of those waza are indeed totally different, they may look similar but both have a different dynamics and principle to achieve the ideal result.
Cant give a better answer right now. Its not easy to explain.