The “X-Factor” is a popular term for the relative rotation of shoulders with respect to hips during the golf swing. A relatively large X-Factor at top of backswing is thought to facilitate high club head speed at impact. Little consideration, however, has been given to how the X-Factor changes early in the downswing.  We tested the hypotheses that highly skilled golfers have a higher X-Factor at the top of the backswing and a greater increase in the X-Factor early in the downswing (“X-Factor Stretch”) than less skilled golfers. Multiple swings of 10 highly skilled (handicap 0 or better plus one long drive champion)  and 9 less-skilled (handicap ≥ 15) golfers were captured with a SkillTec 3D-Golf™ swing analysis system (Skill Technologies Inc., Phoenix AZ). The X-Factor was measured at the top of backswing and at its maximum in the downswing. A contrast of the X-Factor means at the top of backswing showed no significant difference between the highly skilled and less skilled golfers, (t=1.017, p=0.326). Further, the effects of skill level (highly skilled and less skilled)  and swing position (top and maximum) on the X-Factor were assessed using a two-factor ANOVA. The X-Factor averaged for both the top and maximum was 11% higher in highly skilled golfers than the less-skilled players, but this difference was not statistically significant (group main effect F1,17=1.93, p=.18). The X-Factor Stretch occurred during the early stages of the downswing for both highly skilled and less skilled golfers (swing position main effect F1,17=131.57, p<.001), but was significantly greater for the highly skilled players (19%) than the less skilled golfers (13%; group x swing position interaction F1,17=6.90, p=.02). This suggests X-Factor Stretch early in the downswing is more important to an effective swing than simply the X-Factor at the top of backswing.