Knife Fighting Self Defense
...can be as easy as having the right technique or trick in your back pocket. BUT, it's also about using every feasible advantage that you have... and some advantages stare us right in the face without being realized. (On a somewhat related note, I recently watched guy pick up a trash can and smash his machete-wielding attacker over the head several times.) It worked, and it re-enforces the lesson that for true knife fighting self defense, you need to 'use what you've got'.
In this light, we take some lessons from the world of Jiu Jitsu.
Those fancy pajamas that you see Jiu Jitsu fighters wearing are called "Kimonos", but usually are referred to as a "Gi", and they represent every feasible GRIP that you might be presented in a fight. Collars can be used to choke you in 150 different ways. Sleeves can be used to tie you in knots (and also to choke you). The gi is about using what you've got, and if you have a sleeve to grab, you can have a tremendous advantage in a knife fight.
If you can trap that sleeve, your attacker just might lose the ability to use his knife entirely. If you have a couple good moves from a sleeve trap position, you can easily master the game of knife fighting self defense.