In martial arts like Karate, there are pre-arranged forms called Kata (also known as Quan or Hsing) which are stylised ritualised and themed representations of fighting techniques. To analyse these often abstract movements is called bunkai and to then work with another person to apply the resulting technique is called Oyo.
There are several layers to Kata, Bunkai and Oyo study:
1) The Science of Violence: Understanding what kind of purpose the movements would likely have
2) The Science of Technique: performing the movements in an efficient and accurate manner
3) The Science of Learning: The kata being used to drill responses
4) Internal or health benefits: Fast Shotokan type kata can have Calisthenic benefits whereas forms like Sanchin can have muscular (isometric tension) benefits and can also be of internal benefit (ie as in Tai chi and Yoga), improving relaxation, breathing, bloodflow etc
5) State of mind. Kata can help with focus, meditation, concentration, visualisation.
These factors aside if we look purely at the physical self defence aspect of the bunkai, we have various possibilities:
1) Consider the possibility that the application could involve a weapon
2) Consider the possibility that the most obvious application should be applied (ie what looks like a punch actually is a punch)
3) Consider the possibility that the most obvious application should NOT be applied (ie what looks like a punch can’t be a punch and therefore must be a throw)
4) Consider primary sources. Does the work of Motobu, Funakoshi, Miyagi etc actually present a decent oyo for us?
5) Are you looking for something that is not there? Don’t over complicate things. The bow is just a bow – it may look like a headbutt but it’s not
6) Could the technique have multiple applications?
7) Consider changing your perspective. Maybe the attacker is behind you. Maybe you are in a confined space.
8) Don’t be put off by labels and old wives tales. Tekki is not for fighting in a boat or paddy field and Bassai is not for storming a fortress.
9) Don’t be put off by bunkai nay-sayers who will (mis) quote Bruce Lee and say any form study is a classical mess and the mind should be free. it is only by applying constraints that we are able to think laterally about a problem. if somebody told you you could not use your hands, you would use your feet more creatively.
10) Keep it real. Bunkai should be simple and brutal. don’t get TOO creative.
Let’s look at some examples: