Balance is the core element of an effective swing, in part because good balance is necessary to help keep the club on plane. Swing plane is the angle of the shaft at address (1). It can vary from player to player. For consistent strikes you should maintain this angle during each part of the swing: address, backswing, impact and follow-through. Notice in the sequence of Len's approach shot to the 16th hole on Sunday (above left) that his eyes, shoulders, hands and the club are parallel. In the third frame the lines show that Len's body, and shaft, are perfectly on plane.
To learn how to stay in balance and on plane, take easy three-quarter practice swings with the club of your choosing while standing atop a milk crate. (Caution: Please be careful!) With the opening of the crate facing up, put a foot on either corner of the crate's two long sides. If you swing in balance, the crate won't move and your body and the club should be on plane throughout the swing (2).