This means that we are trying to eliminate every single prepatory movement, hesitations, readjustments/alignments and so on. There are many videos on social media platforms of people demonstrating this, often by showing a straight lead (as in the picture), or finger jab etc. Almost always, there are those that criticise the performance, but they're forgetting a few important things. They are not on the receiving end of the action! It is very easy to be able to analyse it from the outside, as a 3rd party, but if you're the one being targetted, you would not have the same calmness, observation angle and so on. The attack is coming straight at you (in this example) so your depth perception is going to affect it. You are also under pressure, meaning elevated adrenaline/stress levels, which further slow down your ability to see what's about to happen. Often we find that we did actually register 'something' but there's not enough time to defend against it. A JKD person is primarely a counter fighter, and being a counter fighter we often need to re-act rather than act. Developing a keen sense of the other persons intentions is key to our succes. Knowing that something is about to happen, rather than responding when it has already happened, is a skill that will develop through years of training.
On the other side is us refining our movements, by repeating the action over and over, working on correct execution of the technique, and there by removing all unneccesary movement, a key element of the JKD fighter being perceived as very fast and being non telegraphic. The founder Bruce Lee was fast, not because he was super human, but because he was a very driven/dedicated person who would train intensely, his training logbook show that he would throw 500 punches of a certain type in a session, just to get it right, or better still, never get it wrong!
We can never get perfect, but we are able to get as close as possible to it, by training. So next time you see a video of a non telegraphic punch being performed and you notice a small flaw, try and put yourself in the shoes of the receiver and consider if you would still have spotted the flaw, or that you'd likely get hit because you didn't see it, or you simply couldn't act quick enough...
Walk On!