You lose distance and notice that you do not make much of a turn during the backswing.
You want to get a little more clubhead speed at the bottom of your swing.
You want to get the most distance out of your tee shots or you find that you are losing power.
You plan on trying to add a little more power to your drives.
Hooking, pulling, or slicing due to poor hand position.
You want to hit a power fade to help the ball around a dogleg or for playing in crosswinds.
You have difficulty relaxing just before an important tee shot or first round of the day.
You keep hitting at the ball instead of through it.
You want to gain a few extra yards off of your tee shots.
You are slicing your drives and naturally have a steep swing.