One size fits all" might apply to some clothing, but it definitely does not apply to golf swings. One look at a golfer like Craig Stadler and another the size of Jeff Sluman makes it obvious that players of different shapes need different motions. However, many teachers try to fit all golfers, regardless of their height and girth, into the same-size swing.

This kind of "off-the-rack teaching" is counter-productive and unfair. The golf swing should be custom-fit to a student's shape, as well as his flexibility, strength, and other natural tendencies. That means the so-called "fundamentals" don't work for all golfers. Many players improve only when they go against the book.

But simply saying "different strokes for different folks" is not enough. I want each golfer to find the best set of basics for his, or her, physique. That way every golfer can make the most of their bodies rather than trying to fight what is natural. With the help of Jim Suttie, a Ph.D. in biomechanics, and T.J. Tomasi, a Ph.D. in motor learning, I devised a teaching system that matches the golf motion to the individual golfer's measurements.

After years of research, we discovered that the pros' swings fall into three categories, depending on factors such as their frame and range of motion. For example, Tom Watson and Annika Sorenstam make similar swings, the result of their medium builds (not necessarily short, but not wide). They are also fairly flexible.

Fred Couples, Davis Love, and Michelle McGann all have long limbs and a wide range of flexibility.

Craig Stadler, Jim Albus, and Meg Mallon are thick-chested and have limited flexibility.

The more we studied, the more important the role of flexibility became in determining swing type. Combining range of motion with body size, we came up with the "LAW" Personal Swing System -- "L" for Leverage, "A" for Arc, and "W" for Width, the three types of swings.

The names derive from each swing's dominant power source. The Leverage swinger (Watson, Sorenstam) utilizes hinging and straightening of levers -- arms and wrists -- and exaggerated hip rotation to generate power.

The Arc swinger (Couples, Love) depends on an upright swing, the club moving well above his body.

The Width swinger (Stadler, Mallon) swings the club away from the body, creating the widest possible arc with minimal arm-swing and maximum wrist-hinge.

Since identifying these types, we've found that most golfers -- amateurs and pros -- fall into one of them. Once golfers know who they are, they can begin working on the proper moves and drills that make the most of their shape and flexibility.

So which are you? A quick look in the mirror will start answering that question. If you have a medium frame, average-length arms and legs, and look like the player in the pink shirt, you likely are a Leverage swinger.

Tall, small-boned, and thin-chested? Do you look like the player in the striped shirt? Then you lean toward the Arc swinger.

If you are large-framed, with a thick chest, short legs, and powerful arms -- like the player in the green shirt -- there's a good chance you are a Width swinger.

But not necessarily. Your reflection is not enough, which is why we devised three tests to confirm your body/swing category. No one test is conclusive, but their cumulative results are very instructive, so keep score as you go along: If the results of all three aren't the same, the total score will indicate the right swing type for you.