A) The Longest Leg Weapon, the sidekick
B) The longest hand weapon the finger jab
JKD is robust with principles and concepts that Bruce Lee developed, one of the key principles is to use your longest weapon against you opponents nearest target. This abides by the concept of Economy of Motion. There are no wasted movements in JKD. I once read that Bruce Lee himself said that he would no less punch a man in his foot than he would kick a man in his head. Why not? It’s simply not economical. I know we have all seen his films chock full of high flying kicks, well that looks good on film but what looks good on film isn’t always practical. It would take longer for your foot to leave the floor and travel to your opponents head than it would be if you just used a punch instead. The delay could cause you to telegraph your attack and offers your opponent the opportunity to block or intercept your intentions. As JKD practitioners we must waste no time or use extra movements. The truth reality based combat is that the simplest techniques work best.
The longest weapon to the nearest target concept is usually used in combination with the concept of intercepting your opponents incoming attack. Given that you have maintained an adequate fighting measure, your opponents incoming attack should allow you the opportunity to intercept them with a stop kick or hit. See the images above for examples of interceptions using the stop kick and stop hit. In image A, here Bruce used his side kick against his opponents knee. He chose this weapon and target because he was out in a longer range and his lead side kick is the longest weapon. Attacking his opponents knee would be the ideal target to do the most damage. In image B, we see them in a closer range. Bruce utilized his finger jab to his opponents eyes. The extended fingers have a longer reach than a punch and when used against the eyes as a target, the fingers do the most damage.