When hitting a wedge shot, if I play the ball forward in my stance it adds loft to the club and exposes the bounce (the rounded sole of the club-head) to the ground. This is great for when the ball is sitting up in the grass in a “fluffy lie.” When I am faced with this lie, I am usually in some tall grass. Therefore, because of the added loft, I am able to take a bigger swing. Taking a bigger swing promotes more club-head speed which ensures that my club gets all the way through the thick rough. Also, the ball will come out high with more spin which gives me some control out of the rough.
Now, if you tried to play the ball forward in your stance when it is sitting at ground level on a “hard-pan lie”, you would run into the problem of blading (hitting the ball with the leading edge of the clubface) it over the green. See picture below:
When you correctly play the ball back in your stance off of a hard-pan lie, you will be able to get the leading edge under the ball. Also, the club will not have as much loft at impact and the ball will come out lower with less spin. In the picture below, notice how you are exposing the club-face to the ball instead of the leading edge which will eliminate the bladed shot.
Next time you are faced with a wedge shot off a hard-pan lie, remember to set up with the ball in the back of your stance!
GB