X Factor Stretch

The “X-Factor” is a term that was coined by John Andrisani of Golf Magazine and introduced to the golfing community by Jim McLean in a 1992 Golf Magazine article. The X-Factor describes the relative rotation of the shoulders as compared to the rotation of the hips during the backswing. It is considered a key factor in the production of swing speed and distance.

Named the X-Factor Stretch, it is now widely considered to be at least as important as the X-Factor itself. More highly skilled golfers were found to have a greater increase in the X-Factor early in the downswing (“X-Factor Stretch”) than less skilled golfers. For example, a highly skilled player might have an X-Factor differential of 60 degrees, and on the downswing, they increase this differential between shoulders and hips to 73 degrees, resulting in an X-Factor Stretch of 13 degrees. What has occurred in this instance is that the hips have rotated significantly faster than the player’s shoulders, creating additional coiling of the torso.

Ideally, just prior to the transition phase from backswing to downswing, the pelvis will slow down, change direction, and begin to rotate forward while the upper body continues to rotate backwards. In fact, the hips move at their fastest at the very beginning of their movement forward in the downswing. With this forward movement, there is an increase in the stretch of the large and powerful rotating muscles of the trunk. The trunk can then rotate forwards with a faster and more forceful contraction because of greater stored elastic energy in the big torso muscles. The result: Greater club head speed at impact.

With our 3D system, we can measure your X-Factor as well as your X-Factor Stretch. We can also use our 3D systems in a training mode to help you learn how to increase both of these measurements using biofeedback audible tones.