Swing theories come and go in golf. Some would say swings theories are confusing, if not contradictory, because golf is such a difficult game to master. Others might say the reason golf is such a difficult game to master is because it is often taught in confusing -- if not contradictory -- ways. The one-plane vs. two-plane swing theory, the creation of teaching pro Jim Hardy, is a prime example of the confusing nature of golf instruction.
In 2005, golf teacher Jim Hardy published a book called "The Plain Truth for Golfers," which quickly became the new darling of golf swing theory. Hardy's theory is that there are two basic kinds of golf swings, and every golfer needs to determine which works best for him. If you are a one-plane swinger, you need to focus on a certain set of body movements to maximize your game. If you are a two-plane swinger, you must focus on executing a different and trickier set of movements.
Peter Jacobsen is one of the main proponents of the Hardy philosophy. After changing from a two-plane to a one-plane swing under Hardy's direction, Jacobsen won a PGA Tour event in 2003 at the age of 49 and the U.S. Senior Open in 2004. In a 2005 article for Golf Digest, Jacobsen boils down Hardy's book to a minimum to explain the one-plane versus two-plane difference. As Jacobsen says, a one-plane golfer stands farther from the ball, turns his shoulders on an inclined plane and swings his arms across and around his chest. It is a more of a rounded movement, and the club moves on a relatively flat plane that puts your shoulders and left arm in line, or on plane, at the top of your backswing.
A two-plane swing is considerably more upright. A golfer stands closer to the ball and swings in a more upright fashion, so the left arm is on a much steeper plane than the shoulders. Jack Nicklaus and Hale Irwin are golfers who utilized a two-plane swing to great effect. Hardy believes two-plane swingers have to make more adjustments during the swing to achieve the same results as one-plane swingers.
Although Hardy was named PGA National Teacher of the Year, his one-plane versus two-plane theory had largely fallen out of favor by 2010. According to an analysis on Mountain Web, some of Hardy's disciples seemed to lose distance and appeared to adopt awkward-looking swing positions. After the one-plane versus two-plane furor, a new theory called Stack and Tilt swept golf for a short time before also fading in popularity. If you are trying to improve your game, an instructor who focuses on fundamentals, such as grip, stance, balance and timing, may be more likely to keep your game on track than an instructor teaching the latest exotic or esoteric swing theory.