Attack 01 / Lead hand
Jab
Action
Start from your stance with the lead foot forward and the weight even on both legs. From the guard the lead fist travels in a straight line from your shoulder to the target: the elbow stays directly under the fist, the rear hand stays glued to the chin, the chin tucks behind the lead shoulder and the rear shoulder is slightly higher than the lead one. The fist snaps back along the same path the instant it lands — it should return faster than it went out. No wind-up, almost no hip turn.
When to use
The measuring stick of boxing: throw it to read distance, to occupy the opponent's eyes, to interrupt their rhythm, to make them flinch, and to pull the guard open so the rear hand has a gap to shoot through. Also the safest way to keep a taller opponent from walking in. In this demo it is a pure feint — the other fighter is not touched and her idle / taunt loop keeps running.
Advantages
The shortest travel time of any punch, so it is the hardest to see and the cheapest to recover from. It keeps you balanced and in stance, it can be thrown while moving in any direction, and it is the entry point of almost every combination. A fast jab wins rounds on its own because it scores without exposing you.
Limits
Power is low by design — it does not stop a pressure fighter who is willing to eat it, and judges rarely reward it as a damaging blow. If it is thrown lazy with the hand dropping on the way back, it hands the opponent a free counter over the top; if the lead shoulder stays low, the chin is exposed behind it.