Well, I'm pretty new to ma generally, and have never trained a knife disarm, but do study what's generally considered internal, so...
If I can see the knife, I'll concentrate on the hand holding it. Feint with the body, and use the 'off' hand (my left) to attack the limb holding it, hoping the assailant buys my feint. Once control at hand or wrist is achieved, twist the hand so the thumb is pushed toward the elbow - I'm no chinna expert, but this usually causes pain. The knife itself is now about 50%-75% under my control, I would think. Using the flat of the hand against the flat of the knife, exert contrary pressure to the blade (once again, hoping my opponent has more or less forgotten about the empty hand they still have free) to fully break the grip of the assailant, forcing him to drop the weapon. Since he's already committed to an assault with a deadly weapon against me, go ahead and break whatever seems easiest to break from the resulting position.
But, more likely I'd get cut bad. Still, the guy was coming at me with a knife. I'd have been cut bad regardless - at least this way I had a slight chance.
All my fight strategy is based on deliberately injuring my opponents. -
Crippled Avenger
"It is the same in all wars; the soldiers do the fighting, the journalists do the shouting, and no true patriot ever get near a front-line trench, except on the briefest of propoganda visits...Perhaps when the next great war comes we may see that sight unprecendented in all history, a jingo with a bullet-hole in him."
First you get good, then you get fast, then you get good and fast.