All of that means that the planets are in perfect alignment and God is on my side, because it's based on a lot of assumptions. I'm assuming that I'm not the original target when the shooter enters the room. I'm assuming that the shooter has fired until the weapon has malfunctioned or the magazine is empty. He's not just stopping to ascertain the damage that he's done. I'm assuming at this point that he's the only person still standing in the room. I'm assuming that he'll be a stationary target. I'm assuming that my first shot will find its mark.