Like he said (very well) test those theories. I use stuff like this in boxing all the time. If the guy looks tired but guarded I step back and drop my shoulders and face like I'm taking a breather and then lunge in with a stiff jab followed by a combo whe nthe opponent relaxes. It works sometimes, but this involves practice - and the jab and combo to back it up with, which also takes practice with lots of different people.
For the record I have actually used the play crazy technique once or twice. I once saw four lads in classic mugger fomration walking up the street about a hundred yards away. I just knew what was about to take place and rather than fight started to twitch a little and mumble. I got to the middle of a road I had to cross and stared after the tail lights of a car just as they saw me and turned to come back towards me. I had been right. Then I ambled forward again but they stopped and turned around again.
I had planned to look at the leader's bandana and say 'Snake!' point at it with my left hand and hit him as hard as I could with my right hand as soon as they came too close and then take to my heels. Fortunately that wasn't necessary. Notice that fighting and running were a large part of the plan.
It won't work all the time though, and is not suitable for many situations - especially if you are to meet the opponent again - a trick will only work once. Psychological stuff must be combined with solid defensive and offensive basics.
For the record I have actually used the play crazy technique once or twice. I once saw four lads in classic mugger fomration walking up the street about a hundred yards away. I just knew what was about to take place and rather than fight started to twitch a little and mumble. I got to the middle of a road I had to cross and stared after the tail lights of a car just as they saw me and turned to come back towards me. I had been right. Then I ambled forward again but they stopped and turned around again.
I had planned to look at the leader's bandana and say 'Snake!' point at it with my left hand and hit him as hard as I could with my right hand as soon as they came too close and then take to my heels. Fortunately that wasn't necessary. Notice that fighting and running were a large part of the plan.
It won't work all the time though, and is not suitable for many situations - especially if you are to meet the opponent again - a trick will only work once. Psychological stuff must be combined with solid defensive and offensive basics.