If you're referring to the drill I'm thinking of, its purpose is to begin placing hits on the target as early as possible from the drawstroke as soon as the muzzle is lined up with any part of the torso in a toe to toe situation where you may be facing an assailant who has already drawn or is ahead of you on his draw. It's probably the best technique available if you should find yourself in that very unhappy situation. Except for that circumstance, I think you're better off going for the high center of mass shots first as discussed earlier.I just read some where about the so called "zipper drill" Put the first round in the belt buckle and then three or four quick shots strait up the center of the torso following the natural rise of the point of aim with each round fired
srothstein's recommendation and reasoning on the hip shot (also known as the pelvic shot, since ideally your round will fracture the pelvis and disrupt the structural integrity of the bone structure that's needed to stand, walk, or run) is sound. It's one of the best ways to quickly stop a full running attack like the type you might face with a knife armed assailant. It might even be a preferred first shot under this circumstance because even with 2 rounds in the heart a determined subject can continue to function almost normally for around 15 seconds until oxygenation of the brain drops below the level required to maintain consciousness - plenty long enough to ruin your whole day.
Keep in mind that with the pelvic shot, although the offender may go down, he will not necessarily be out of the fight and could still fire a weapon effectively if he chooses to.
It's a good idea to practice on both secondary target areas (head and pelvis) so you have both of those arrows in your quiver and can decide which best fits a given circumstance you need to resolve.