Why? Because they look in the wrong place when setting their body. You should be looking for two parallel lines, like two railroad tracks and they never cross in front of you. Maybe behind you, but never in front.

One line is your club pointing at the intended target. We will call that the outside railroad track. The body line, as you set up to the ball with your shoulders, hips, knees and feet, are on the same, the inside railroad track.

The biggest mistake a player will make is setting the club and body while looking at the intended target. You should look first at the target, set the clubface, then look about 10 feet left of the target and set your body line.

To practice correct alignment, set a club on the ground while hitting balls slightly left of the intended target. Now take your address position, first setting the clubface to the target on the outside track. All this time you are looking out. Now come back to the club on the ground and see if your toes are parallel to that club.

If the toes are parallel, you are in a square position. If your feet are pointed right of the target, you are in the wrong position.

Try this and your alignment should improve.