This is something that i often do to...mess with my opponents head.
It had been pulled on me once before but i wasnt quite sure what had been done.
If youre good enough, lessen the distance of your punches (BUT I WILL WARN YOU, YOU MUST BE GOOD TO DO THIS)...its kind of a literal sense of "pulling" your punches, because you arent fully extended.
This does two things.
1. Its lowers the power in your shots
2. It gives your opponent a fucked up sense of your distance

So..what can you do with this?
Say...pull this move off for...1 round. 2nd round...about halfway through, if he has your farce distance and his own rythm, start to REALLY let go, extend you arm properly, punch "through" your target and not only will you hit him a couple of really good shots before he has figured out whats goin on but itll fuck up his rythm for the rest of the fight.

Why am i telling you this?
Oft or not, most people will do this "technique"...i would prefer trickery...when they have little to no experience (i would know, thats how i was caught) or technique. Many fighters will focus so much on releasing and drawing back their punch that it never reaches its full extension.

Not really sure if thatll help.

But yeah...hitting your opponent will help you win fights too.......? i dunno :P