Greg Ellifritz of Active Response Training has years of experience in the field of knife fighting. Much more than my very limited experience.
That said, he has come to the same conclusion that I have come to understand.
Folding knives are far less efficient than fixed blade knives. Take a look at his article and see his reasoning.
Written by: Greg Ellifritz The next time you see a police officer, take a look at the pockets in his or her pants. It’s likely you’ll notice the majority of them have a folding knife clipped there. But what about fixed blade knives? There’s a good chance you won’t see anyone carrying a…
via Should Police Officers Carry Fixed Blade Knives? — Active Response Training