I've got a civillian friend that has been in one gun fight. That fight required seven shots. If I remember correctly five shots hit in the trunk of the attacker's body. One hit a tree across the street and one was lodged in the head rest of the attacker's truck.
The attacker pulled up got out of his truck and stood behind the door. Then he opened fire. Not a normal scenario, but it has happened.
I have had to draw three times. I have never had to fire a single shot. It is all a crap shoot. The most or the least don't matter. What matters is having enough for the situation you're in.