Here are my two:
1. Punching an incoming punch or kick
I’ve never actually seen this taught as a formal technique or self-defense step but I’ve heard it mentioned in tae kwon do, kung fu, and also have heard it as a possibility from a karate guy. I’m sorry folks but this is just a bad idea!
Don’t believe me? Hold your arm out straight and make a fist. Now make circles with the arm held out straight. This is the range of motion you are trying to cover. Yes, a straight punch is straight and can be telegraphed. However, good luck trying to hit such a small spot if it’s coming at you full speed. Worse still, even if you hit their fist or kicking foot your probably going to hurt yourself as bad as you hurt them. And bending down or dropping low to hit a foot with your fist is just dumb. As evidenced by the above photo, it opens your head up to a hammer fist, rear kick, knee, front choke, etc. Worse still, who is going to stand their like a dummy while you drop low to punch their foot?
If you want to check a punch try using an arcing elbow strike. Mui Thai, the Filipino arts, and even karate or tae kwon do have versions of this. If you miss your face is still mostly covered by your arms.
2. Rising block knife defense
Just go to 1:09 of this video to see why this is a bad idea.
There you have it! So what are your two worst martial arts techniques?