http://community.shtfschool.com/forums/topic/the-reality-of-a-knife-attack/ more discussion here.
I never had a formal class in martial arts, I grew up with 4 brothers. We had enough training with wooden knives, swords, spears, slings, and shields to join the Roman Legions. Our play fights almost always turned into real fights. Kind of amazing I have eyes with the number of near misses I took from flying missiles and stabs to the face. Got poked in the white part one day with a old finger nail file. Really learned a leason that day about keeping your distance and controlling the weapon arm of your opponent. When it comes to blows with blades bigger and stronger is better. Keep them away and counter strike the opponent’s wrist cutting the ligaments behind the thumb or back of the elbow cutting the ligaments. If they close the distance slash the weapon arm ligaments at the bottom of the bicep.
A shield really helps, a book, laptop or any thing that can be used in the weak hand to block a blow gives you the opportunity to strike with your strong hand and end the fight a quickly as possible.