Golf Digest April 2012 p. 126
This article is the kind that so often results in players concluding that Golf Digest is more a source of headache than help. Reading the following will help you better understand this article and introduce you to how careful we need to be when we are attempting to learn to play better.
Chuck begins by referring to a problem of "rolling the elbows". Unlike the wrists which are a ball and socket joint and can be rolled, the elbows are a hinge and cannot be rolled. He mentions that the clubface should not be facing skyward. In the "N" photo notice that the arms and elbows are nearly identical with the "Y" photo. The difference is that Chuck has rolled his wrists (note the orientation of the black logo on the back of his glove). Secondly, because the wrist are ball and socket the don't "naturally bend the left wrist flat". They can bend any way we want them to. Finally, he explains that one elbow bends and the other stays straight. At Chuck's age (any most anyone over 30) we have lost our full range of motion in our left shoulder. To make a full backswing as Chuck has done, you will note that is left elbow is anything but straight.
While, Chuck does a good job of describing the legs' movement in the hip socket, this clutters a much simpler idea. When you make your backswing, maintain the balance you have at address. If you keep that balance you will not shift your weight laterally and will turn instead. Before we move on to the next section, look at the "Y" photo and notice how flat the back of left wrist is relative to the forearm. In this position the clubface is severely out-of-square. If Chuck's swing returns the club to the ball with the wrist in that position the drive will land deep in the right rough. To see this for yourself, set up with your driver as you normally would. Leave the club head positioned behind the ball while you move the grip end of the club so you can flatten that left wrist. You will see that the clubface is now facing to the right.
Chuck gets a little confused about his anatomy. Your shoulders are not on a ball and socket joint (your arms are). Your shoulders rest on the top of your spine like the top of an upper case "T". As the swing passes the address position, the hips and shoulders should turn in sync resulting in no twisting of the spine. At the end of the swing the hip line and shoulder line should be close to parallel.
Bottom Line: When we address the ball, the back of our left hand and our left forearm are at an angle to one another. The more you play the club toward the center of your stance, the bigger that angle. If you want to return the club to the ball as you have it at address, you do not want that angle to change during the swing.