Used to do something similar at one point in time. Eventually changed it up a little.
The person throwing the punch isn’t actually trying to strike his training partner, he’s presenting himself in a fixed position, open to a counter that isn’t necessary. Why it isn’t necessary is because the puncher isn’t trying to hit the defender, the punch is merely an extended arm, frozen for a moment in time.
While it can be helpful, somewhat, for new white belts, it can be extremely detrimental for others. It tends to give a student a false sense of distance, and a false sense of timing. That can really suck if someone actually tries to punch you in a non controlled environment.
What might be a good idea is to gear up with some gloves, mouthpiece and head gear. NOT TO BANG AWAY, but to train safe. Go through the drill the exact same way, but close enough that you just might get hit. Teach good control and implements it into the exercise. Then the puncher can say to his partner, “Okay, this what I’m going to throw and try to hit you on the chin, the forehead, wherever.”. And when I say hit, I do not mean hit hard.
And then, before you start, have the puncher give him a little shot. A well controlled little shot that shows the defender exactly where the punch is going to hit. THEN go through the exercise.
Another way - again, have the puncher in the right distance, give each other that little shot, THEN have the defender never defend it the same way twice. Duck it one time, slip it another, step off and in to both sides, step in and jam, stop back and evade. Let the defender move on his own freely, getting an idea what might actually work for him.
It’s important that the two practitioners communicate with each other. “How was that one? Want me to throw it faster, slower, wider, lower etc?”
You need your own trial and error, under the trainers guidance of course. And that kind of exercise helps more when it’s done for an hour or so.
And from both fixed stances and moving stances. Sometimes have the puncher start from ten feet away, casually walking towards him, sometimes looking right at him and sometimes not looking at him at all. That in itself gives the defender a better way to understand distance, especially a distance that is closing.
And again, you have to have the practitioners communicating with each other. And to those that say "we don't talk during class."
Yeah, we don't either. Unless we're communicating.