With respect to tachiwaza (throwing skills) in the traditional Kodokan gokyo, how many of those throws have you ever seen or practiced in a self-defense context? Or, put another way, how many of those throws have you either heard of being used in self-defense, or can even imagine cropping up on the street? For me, it's mostly the following list...
- deashi, kosoto, osoto, hiza, ukigoshi
- kouchi, ouchi, ogoshi, seoinage
- teguruma or kataguruma
...and that's about it. With greater than 25 years of martial arts experience, I can only come up with about a dozen of the Kodokan throws that I've ever heard of being used on the street - or that I can realistically imagine ever coming to pass in a fight. Sure, anything can happen, but we're really not into preparing for every bizarro eventuality. We're generally more into probabilities than possibilities.
So, why do we have 40 throws (or 65 depending on who you ask)? Why not spend more time on the down-and-dirty dozen that I listed above?
For one thing, we're not just practicing self-defense. The other throws are part of the art. Also, depending on the ruleset under which you compete, the rules might create situations where some of those other throws might be viable.
But personally, I think that the main reason that we have all that extra material is because when you work on those situations, it makes you better at those more fundamental throws that I listed above.