A fear that will make you nervous and out of control. You will be unable to defend then. That means you are in panic situation. So never ever get afraid of your opponent although opponent is armed with knife.
Kungchido defines the ranges of sparring refer to http://www.kungchido.com. Most likely you will have close combat in most of the cases. But medium range may apply in some cases, if you intend to use your kicks against armed opponent. But before going to combat with your open hands with the armed opponent with knife make it sure that his intention is clear and you can not avoid and you can not get away from the situation.
If, there will be any slight chances do not hesitate to give anything to armerd person/opponent. It may be your money, personal belonging, and car, Jewelry etc. Try to get away as quickly as possible from that location. Life is most valuable thing in the world. If he wants your life then you have no choice. In that case you have to prepare to be ready for full phase combat and not to give up. Use your all skills intelligence See article Kungchido a style without form
When you will fight against opponent armed with knife you have inevitable injury. Ready for that what you have learn in your self-defense classes, literatures are great resources but it will be hard to implement in perfect manner. So any cut of knife or if you will see blood means not to frighten and give up. You have to fight all the way with full faith and might.
You have to look for any opportunity to knock your opponent down with attack or counter attacks. Screaming will help during such combat to draw the attention of surrounding and additional help. If you will get a slight chance to get away from the on going combat do not hesitate to walk-away and save your life. If you will take the full control of fight first thing you will do will be knock down and get knife away from armed opponent. If you feel and confident that you can dominate the opponent go to closed combat but make it sure that any of his/her attack shall be deflected from your body first then quickly attack on the neck blocking knife or grabbing his wrist/hand/arms/shoulders, which is holding knife then add quick attack on groin/neck/leg to knock him down or bring him up to unconsciousness.
See below three way of defending the opponent armed with knife:
Pooja Joshi & Nijel Thomas in action
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