Currently reading 長鎗法選 and deeply analyzing very single bit.
Will share my thoughts when I am all done. Going to test the principles and techniques described with a compliant partner. I got two long ash poles, each with it's "spearhead" of foam padding and tennis-ball core wrapped in duct tape. It should have approximately the same heft and balance of a legit spear... After we're comfortable we'll put on the sparring helmets and test it non-compliant.
So far I have concluded that "inner-circle" and "outer-circle" is a bad translation. It's more like "inside my circle" or "outside my circle"... and it's better described in "modern martial arts terms" as my inside/centerline area and outside/back/flank.
Anyone have art work or period photos of old Chinese spears and/or spearheads?
Or, better yet, pictures from your own collections?
EDIT:
This is a pretty good series from Hong Kong, in this video of Xing Yi Quan (no surprise) there's spear work. They use the same terminology as 長鎗法選.
https://www.youtube.com/watch?v=clgG8HkJELw