Inside Approach: My swing got too upright (red arrow) in the late '70s. I worked to flatten it, promoting a shallower downswing path (yellow).
JACK NICKLAUS: In the late 1970s, I was getting into a top-of-backswing position that was so upright I couldn't hook the ball when I wanted, and if I did hook the ball, it was a pull-hook. That's no way to play golf. I was swinging down at too steep an angle, and when you do that you don't transfer 100 percent of your power to the ball.
A full release of the club is when your right arm crosses over your left through impact with the clubface turning down. It's almost impossible to release the club fully if it's cutting across the target line, from out to in. That causes you to instinctively hold back your arms and hands to keep your shots from going left -- a blocking type of release that usually results in a weak pull-slice.
Working with Jack Grout in early 1980, I got my hands into a deeper (more inside) position on the backswing by turning my shoulders more and tilting them less and by swinging my arms on a shallower plane. This allowed me to deliver the club from inside the target line. When you swing down from the inside, it's nearly impossible to release too soon.
After making those changes, I won the U.S. Open and PGA that year. That deeper backswing pretty much stayed with me the rest of my career.
JIM FLICK: In my 15-plus years working with Jack, I've been essentially another set of eyes for him. I've tried to keep him on the same track that Jack Grout put him on.
It seems the only significant changes they made over Jack's career was to get him a little more centered over the ball -- early on he played more powerfully from behind the ball -- and to swing the club more around him, which is what he means by swinging deeper.
But these changes have always been designed to help him use the club more efficiently, reacting to what his ball flight was and what he wanted it to be.
There's a lesson there for all of us: Don't just position your body in a certain way or make a certain move because someone else does it. Only make changes based on how you want to use the club, or what you want the trajectory and curvature of your shots to be.
That's part of Jack's genius. He never changed just for change's sake. When he made adjustments, it was always to better control his golf shots.
NICKLAUS writes articles only for Golf Digest.
FLICK, a longtime Golf Digest Teaching Professional and PGA Golf Professional Hall of Famer, worked with hundreds of amateurs and tour players including Jack Nicklaus.