When you defend yourself do you use Karate, Jiujitsu, Aikido, Boxing, Krav Maga? No!
You use your body and your judgement! The aforementioned are just training methods to familiarize your perception, and your reaction with prescribed methods of movements.
The best training system needs to prioritize the most efficient possibility from any range and angle and respond to it with the most efficient reaction...
when people say that Krav Maga has no rule they are completely wrong. One of the rules Krav Maga has is to use any option they have in a fight according to the need knowing that in order to save your life you do not have the luxury to stop and think if you are breaking any public law.
The rules of the training method is to acknowledge the limitation of the Human Body and therefore chose the most efficient path to give the defender an advantage of being one step ahead.
Observing Martial Arts Training Methods, I think one of the biggest problems is doing a technique without really knowing what it is for, when to do it, and what the opponents options are. Remember that you are not kicking or punching a tree!
You have a live opponent with a brain that can execute attacks and defenses with his body in the speed of a cheetah. You need to know a lot more about the human capabilities before you consider training in one method or another.
Imagination is more important than knowledge. (Sign hanging in Einstein's office at Princeton ).
"The essence of Krav-Maga is economy of motion coupled with imaginative embellishments on the other martial arts" (Quote: Immi Lichtenfeld)