In the video above I illustrate an empty-handed defense sequence that was taught to prison guards locally. My friend could hardly keep from laughing as this was being demonstrated. The question is, though, how can we tell good techniques from bad techniques? And I’ve had people try to justify techniques that are lackluster at best. Against multiple opponents, a bigger opponent, an armed opponent, or hardened prisoners, you need the best technique.
To decide what is good technique, we must weigh them against principles, not whether or not a technique looks awesome.
One principle of good technique is "cover," meaning that you are protecting yourself as you attack, and exposing yourself as little as possible. When you lift your hands over your head you leave yourself open from the head down. When you punch with one hand while the other hand droops at your side, you are not covered. In MMA and boxing we see repeatedly that fighters who leave openings get knocked out.
It’s not a good idea to cross your arms or to keep one hand on top of the other. It’s too easy to get trapped. And hitting empty-handed like this makes no sense, although the double-handed "judo chop" always worked for Captain Kirk. In the video we see the double hand chop (at 8:17) was the most iconic of Kirk’s fighting techniques.
Are you really going to bet your life on this?