The punch travels only at a short distance to the target, as shown in the video below.
Besides being the fastest punch, the straight lead is also the most accurate because it delivered straight forward, at a close distance, and your balance is left intact.
Put some "zip" into your punch by snapping it just before the impact. Keep your hand loose and tighten your fist only an instant before contact. To put explosiveness in the blow, utilize the flowing-energy concept by adding heaviness in your hand.
The straight lead is not an end, but means to an end.It is not a powerful blow that will knock your opponent flat with one punch, but it is the most dominating punch in JKD and is used profusely with other combination punches and kicks.
The leading straight punch will have more sting if your pivot your hips and utilize all the other functions for a heavy blow.
The Leading Straight Punch
( Leading Straight Punch Video )