Jeet Kune Do is a Concept based art and has a concept of fivefold path at its core. The five steps of discovery of truth of combat are :
One must train in all ranges of combat and not be obsessed with any particular range or technique.
Make the techniques / tools that are useful in a combat situation your system
Reject / get away with all the flowery techniques which do not have direct application in combat.
Develop the thus absorbed techniques to suit your skill level, body weight in relation to the opponent your own style of fighting.
The final test of a technique is the ring itself. The techniques which are made as part of ones system of fighting need to be tested in a combat situation and validated about its usefulllness.
In order to absorb / reject the techniques for making part of ones system of fighting we need to evaluate a technique based a set of principles. There are about 6 most important principles of Jeet Kune Do which can be used to do so.
"HACK AWAY THE UNESSENTIALS" Work with Fewer resources / weapons Mechanically, the more parts a machine has, the greater the chances of it breaking down. Accumulation of techniques only adds complications. Being simple in nature, JKD believes in few tools practiced to the point in which they are extremely efficient. Hence simple tools like the lead jab and lead side kick to he knee are perfected.
"SHORTEST STANCE BETWEEN 2 POINTS IS A STRAiGHT LINE" Be non telegraphic, A line, being the shortest distance between two points, is the most logical path rather than a curved detour to reach the final destination.
In being direct, no excess motion is exerted. For example, If an assailant grabs your wrist, some forms of martial arts may teach you to stomp on their foot, lock the wrist, take them down to the ground, and then finish them with a strike to the throat. The direct approach would be to strike them in the throat right in the beginning. Hence there is no punching from the waist. Also, Interception is preferred to Counter & parry as it is a more direct path to the goal.
"LONGEST WEAPON- NEAREST TARGET & HARDEST WEAPON – SOFTEST TARGET" Attack Primary Targets i.e. Eye & Face, Groin, Knees & Shins. JKD believes in absorbing the useful and rejecting the limitation. Only techniques which work are taken. For e.g. the sport rules of various fighting are discarded and the foul techniques are imbibed. JKD uses any means necessary to accomplish this task. If grabbed you may bite, scratch, or pull hair or whatever best fits the situation.
"NO WAY AS THE WAY, NO LIMITATION AS LIMITATION" Be Open to everything JKD is open to newer ideas and concepts which work. It is a constantly evolving art. Principles from Filipino Martial arts now area regular part of JKD teaching curriculum worldwide.
"BE SOFT YET NOT YIELDING, BE FIRM YET NOT HARD" If he pulls- push, if he pushes-pull, take him where he wants to go! JKD believes in flowing, there is never an opposition to the forces and energies exerted by the opponent. All JKD techniques and responses are in accordance with the ‘flow’. JKD does not rely on one specific technique or another to counter an opponent. You should be able to adapt to the situation at hand. As an attack approaches, you adapt to it with the appropriate response. The opponents attack becomes your attack, as you fit into the opening created. Deflective parrying is preferred to rigid blocking. The rigid and unbending is the disciple of death, the soft and yielding the disciple of Life.
"KNOWING IS NOT ENOUGH, YOU MUST APPLY & WILLING IS NOT ENOUGH, YOU MUST DO" Enter and Exit to Ideal Range, where you have the advantage
Practitioners do not wear uniforms, they do not practice forms, and they don't waste time with complicated techniques simply because of tradition. Shoes are worn, and training with equipment is given a lot of importance. Kata was vertical death, joked Lee.
Also the JKD exponent defies conditioning. The JKD man prefers to condition his opponent to a regular rhythm and then break it. He himself remaining free and resistant to conditioning.