First off, I'm not interested in any responses from the Ninja clansmen or from those who source their information from them, so I'll start by stating that right now. I've occasionally read and heard about the idea of Bugei Juhappan. I've also wondered; where did the idea of enumerating them in that fashion (i.e. specifically 18, or for that matter, specifically counting them at all; maybe it was all just "soldiering" or "military stuff" or just "fighting" to them?) come from, and was it truly as relevant a concept as some may make it out to have been? Obviously, warriors in a given time period would have presumably have been expected to have achieved proficiency with the major weaponry and major military paradigms of the day. But how long did the applicability of "18 martial arts" even last? (I'm having trouble believing that, say, a school from the late Edo period would necessarily have bothered much of anything with sojutsu, not to mention that firearms practice would scarcely have been applicable before the introduction of firearms.) Was the concept of juhappan a contemporaneous idea, or was it something that was written back into history? Thanks for any who entertain my clueless question with a serious answer.