Besides talent, there’s one thing golf’s greatest players all seem to share: a never-ending hunger to improve.

Tiger Woods famously revamped his swing after winning the 1997 Masters by 12 shots and went on to even greater heights. Jack Nicklaus enlisted the help of short-game guru Phil Rodgers in 1980 and won the U.S. Open and PGA Championship at age 40.

Phil Mickelson was riding the wave of winning three major titles in three years when, in 2007, he decided that a more compact swing would serve him better in the long run. He said goodbye to his longtime coach, Rick Smith, and went to work with Woods’ former mentor Butch Harmon — widely regarded as the best teacher of his era. Harmon scaled down Mickelson’s overlong action using the same methods he’d employed with Woods a decade before.

Results came quickly. Mickelson won the 2007 Players Championship on a golf course, TPC Sawgrass, requiring more accuracy and discipline than he’d typically shown. Later that year he outdueled Woods, his old nemesis, to claim the Deutsche Bank Championship. Mickelson added a fourth major victory at the 2010 Masters.

Mickelson’s results have been up and down since then, perhaps owing to his wife Amy’s battle with breast cancer and his own bout with arthritis. But he remains one of golf’s most compelling and popular stars, proving that some things never change.

Mickelson’s signature: An extremely long backswing, with the club dipping past parallel and pointing “across the line.”

Who else does it: John Daly, Bubba Watson

This was the primary reason Mickelson sought Harmon’s help. Always an aggressive player, Mickelson’s let-’er-rip mentality often got the best of him. Thus, his arms would continue moving after his shoulders stopped on the backswing, taking the club too far and disconnecting arms from body.

At the same time, Mickelson was “loosey-goosey” with his lower body. His hips would over-rotate, causing his right knee to point well inward on the backswing. This was similar to players from previous generations, but out of line with the quieter lower body action of Mickelson’s contemporaries.

Another unusual aspect of Mickelson’s pre-Harmon swing was the movement of his head, and indeed his entire body. Viewed looking toward the target, Mickelson would actually sway back away from the ball several inches and maintain this distance on the downswing – an almost unheard-of motion among top players.

Bottom line: Mickelson needed all of his remarkable talent to overcome the abundance of moving parts and idiosyncrasies in his swing.

What it looks like today: Five years after hooking up with Harmon, Mickelson still reverts to his old form from time to time. But when he’s on, the differences between his new swing and old are obvious.

Harmon instituted several fundamental changes, widening Mickelson’s stance to restrict his hip turn and moving his ball position slightly forward. Mickelson’s takeaway is now less to the inside, with the clubhead “outside the hands” – a hallmark of Harmon’s pupils. At the top, Mickelson’s right arm is extended well away from his head but stops short of vertical, and the club is close to parallel with the target line instead of pointing across the line (to his left).

Also, Mickelson no longer leans away from the ball during his swing – at least, not on his good ones.

How it can work for you: If your swing suffers from too much motion and length, take note of Harmon’s work with Mickelson. Specifically:

• On full shots, stand with your feet shoulder-width apart, meaning the insides of the feet match the outsides of the shoulders.
• Focus on keeping your left (lead) arm extended from the head throughout the backswing to create a wide arc.
• As you complete the backswing, the arms and shoulders should stop moving at the same time.

From here, you’ll be in a compact yet powerful position, promoting a more efficient, low-maintenance downswing.