Hi josh, long time no talk!
Thanks for the information. So in essence, we can break down the major dao types as so?
Yan Mao Dao - straight w/ curved tip, thus less effective slicer
Liu Yie Dao - gently curved thus a better slicer without totally sacrificing the thrust
Yan Chi Dao - less curved but has a clip point, thus retains some slicing ability with a better thrust
Pian Dao - optimized for slicing like a tulwar blade
Niu Wei Dao - optimized for cleaving/cutting through, losing an effective thrust
Now what piques my interest is how come Yan-mao and Liu-yie were more popular, followed by the niu-wei in the Qing dynasty? If the Yan-chi had both slicing and stabbing ability, it, in some ways, has improved utility over both the yan-mao and liu-yie right? Or was the advantage so small that it didn't make a huge difference?
EDIT: Also, many of these "clip points" have bumps and don't seem to actually be sharpened... unlike the clip points on bowie knives which are often sharpened or very narrow almost like a second edge. So the Yan-chi blade shape can be thrusted better perhaps, but wouldn't those bumps, etc. somewhat impede a clean, deep stab?