Why The V's Point To The Back Shoulder
In order for you to keep the clubface square at impact, the V’s must be pointing at the back shoulder during your setup (Image 1). This is due to the fact that when you strike the ball your body is not in the same position as your setup. It’s important to note that at impact the V’s will now be centered directly in line with your head (Image 2). This is how you know you have squared the clubface at impact.
There is a significant difference from Figure 3 "Setup" to Figure 4 "Impact". You can see in Figure 4 how much the hips have rotated around the body, the back shoulder has dropped under the golfer's chin, the forward shoulder has raised up and the hands and arms are much further forward (closer to the target) compared to Figure 3.