When I watch a total expert at the Jab, like Floyd Mayweather, I look at the components that make up that incredible Jab.
In this particular example, it is the feet that are incredibly important.
They allow a change of distance, angulation, speed, timing and power increase WITHOUT telegraphing.
Most people just look at the actual Jab arm and say it was quick.
There is MUCH more to it than that.