In golf, it is hard to feel how to take the momentum of the club back. Here's where the front loader drill comes in.
If you start the club back and the weight of the club stays towards the ball, you are doing what the pros do.
If you feel the momentum during the change of directions, you will improve drastically.
There are two reasons people come over the top. Regardless of which one affects you, we want the momentum of the clubhead moving towards the ball.