Consistent ball position produces more consistent shots. Most golfers do not understand where the ball should be positioned in their stance and how it relates to the width of your stance.
Too wide of a stance may turn into a balance issue. Your stance should vary with the clubs you play but if your stance is abnormally wide it can cause swing errors.
Ball Position and Width of Stance
This video is gold and contains a lot of information! You will definitely want to repeat this video several times.