One could have their club enter the sand 2″ behind the ball an hit great sand shots and hit terrible sand shots. Even still, people continue to obsess about where the club should enter the sand. I believe this focus is one of the main causes for people’s fear of hitting poor bunker shots.
The first piece to understand is the term Low Point, which refers to the absolute bottom of the swing arc. Combine this with Divot Depth and we are on to the real source of hitting great bunker shots.
In the scenario above where the club enters 2″ behind the ball, you will hit a long thin shot if your divot depth is only .25″ below the ball. A chuncked shot will result from going 2″ below the ball and a good shot will come from being rounghly 1″ below the ball. These numbers can change greatly based on the firmness of the sand because a soft beachy surface will allow the club to dig much easier. Conversely, with very firm sand it will be difficult to go too deep.
If your Low Point is too far behind the ball, it will become very difficult to have the club travel the correct depth and speed by the time it gets to the ball. This can lead to short flubs if the club is moving slowly and if the club exits the sand into the ball, the dreaded skull. If your Low Point is too far ahead of the ball, your tendency will be to skull the shot as the club is still traveling downward or chunk the shot from coming in too steeply.
This is why I prefer my players to keep their focus on getting their Low Point under the ball with the desired depth for the shot and surface they’re playing from.