The example video was a 'singer attack' - that's where the attacker comes in like a singer sewing machine, rushing forward and stabbing repeatedly. It was pretty much refined on the prison circuit as I understand it and it's highly effective.
Defense against it is completely about making distance. Standing there with your coat out for defense is not something I think I'd ever teach. Actually I think my usual first defensive move taught to students about knife fighting is the reebok or sneaker defense - i.e. start running. Most of them start laughing but the truth is that the 21 foot 'rule' exists for a reason. If a knife is already in play and your weapon isn't drawn then there's a good chance you're at a huge disadvantage. Your best bet is to make as much distance as possible and use your limbs if necessary to protect your vital organs. If you can grab their hand, go for a keylock/the STAB method and you can use that powerful two on one grip to control the knife hand.. assuming you're unarmed and are in a position to grab it. There's a reason that the highest echelons of Arnis are "empty hand vs guy with a weapon" - because it is seriously difficult. I've been doing Arnis (not to mention judo, boxing, & karate) for over 12 years and I don't feel comfortable in that situation yet. Especially if they're even semi-competent with a knife.
Your best friend is awareness of your surroundings. Don't get caught off guard and you negate 99% of the attackers advantage in initiative. Be mobile, keep your distance, etc.
If it ends up on the ground you are in serious SERIOUS trouble. There's nowhere to run, and that knife can have the minimum distance necessary to inflict maximum harm. Controlling the knife hand becomes more difficult as well, moreso if you're on the bottom.
My kind of thread, thanks OP!







