So let's broaden the topic a little.
Punch Type 1: more or less evenly distributed ( can be over the front foot a little, over both, over the back foot a little).
Punch Type 2: fully coomitted, weight over front foot.
Is it fair to say that both have their place in one's arsenal. I've been experimenting with type 1 and I can see that it is useful at mid range, for sticking and moving, for counter punching, etc.
I can also see that type 2 is good after a double jab, moving in on the opponent, going from outside to inside and generally knocking someone's head off.
BTW: By type two I don't mean falling over maladroitly as in the photo a few posts back. Center of gravity over the front foot, not over the floor two feet in front of the front foot.
I dont really have a lot of formal training in striking, but from what I learned from my cousin who used to Box down in Poco, BC... he says to keep the front knee bent. So by doing this I have slightly more weight on the front foot after the point of impact, but about 50/50 at the point of impact
For an exclusively power punch, if I was just punching without having to worry about anything after the punch, I probably have my weight just about entirely on the front leg at impact. I might almost even hop (driving off the right leg) onto the left leg, hitting with the right hand.
Of course, the sort of situation where I could completely commit to a punch without worry of a follow up doesn't happen often, so I am usually less than 100% on the lead leg. Even if I was, I wouldn't stay there. Everything in an open environment is a balancing act- power vs. vulnerability in this case. So the punch varies according to the situation, of course.