Having skimmed through this thread again, I realize that I'd passed over two of Spectre's posts without noticing them prior to making my last one; had I read them, I would have phrased things a little differently. My post comes off as a bit abrasive and that was not what was intended. My apologies for being inattentive.
(I will not be editing it. I may edit for grammar or to add something, but I do not edit existing content.)
Now returning you to your regularly scheduled discussion...
However, their must be some common design characterisitcs that work more efficiently....
Indeed -- for certain people, hence my diatribe above. Allow me to present an example if you will. Consider these two designs:
Here we're looking at the SE Asian
kerambit and the European
rondel. Both were successful killing knives. ("Successful" in this case meaning that they were at least somewhat efficient as weapons and remained in use as such for at least a century.)
The kerambit was probably an agricultural tool that was eventually pressed into service as a weapon. It can be held in a variety of ways and is primarily a slashing or cutting weapon. It can be concealable and does not feature a guard. It has uses outside of fighting. The rondel was more than likely meant from the start to be a weapon and was very limited in its cutting abilities, being optimized for thrusting attacks. It too can be held in a variety of ways, although many of them are different. (Indeed, it was often used two-handed in a halfswording manner.) It's not generally concealable, has a guard, and has little utility as a tool.
Both are killing knives, yet they are about as different as such things can be. The kerambit was appropriate for SE Asia. The rondel was appropriate for the battlefields of Europe. Both can kill someone efficiently; which one is preferable depends on who's using it and who they'll be using it against. This is why I say that it's hard to pin down any one feature as being superior to all others -- it really depends on what you want it for.
Again, it may be more useful for us to discuss particular features and how appropriate they are. Guard or no guard? (And what kind?) Tip-heavy or neutrally balanced? One edge or two? What kind of point? Everything has an advantage and a drawback, and just about any conceivable feature has been tried by someone, sometime, throughout the history of mankind. Everything works for something, but not everything works for any particular job.
I'm not trying to be difficult or evasive with this, but asking about the optimal features of any particular tool is akin to asking about the optimal features of a vehicle -- without more information, we're simply offering personal preferences with little context. My sports car recommendation may please someone who wants to drive fast but if you're looking to haul a cord of wood, I just set you in the wrong direction with it.
Dear lord, I'm starting to sound like a gunzine writer now.
This isn't helping, is it?
Edited to add: if there is any common thread, it's that they're all knives and that they can all either cut, or thrust, or both. There is no other single unifying feature.