Pros nail this trail-arm position. How to copy it for a better backswing

The setup is critical to allowing the club and body to move properly in the backswing. On tour, nearly every player starts with a soft trail arm. The right elbow for right-handers is slightly bent at address and when viewed from behind, looking down the target line, it sits below the left arm (above).

This serves two crucial functions. First, it squares up your shoulders. Many average golfers who fight a slice tend to get their shoulders open in the setup. This often happens when the right arm is too internally rotated because it’s rigid, which shoves the shoulders open. (I demonstrate that in the video below.) With open shoulders, you’ll tend to take the club back too far outside, which leads to that dreaded out-to-in path coming down and a slice.

Blackburn's Moves You Can Steal From the Pros: Keep Your Trail Arm Soft | Move the Clubhead First | Turn Your Ribcage | Push Your Butt Back | Swing Wide on Wedge Shots | Use Your Pivot for Chips

A softer trail arm also promotes an on-plane backswing, where the club moves on the plane established by the shaft to the ground at address. The trail arm controls the structure of the backswing, and by keeping it bent slightly at address, it’s easier to fold it going back. The clubface will naturally open a little as you bend the right arm, which will put you in a perfect backswing position every time.

To determine if your trail arm needs softening, take a picture of your setup from down the line. From this angle, you should see the trail arm sitting below the lead arm. Feeling like your trail elbow is pointing more toward the center of your body will help get you into the proper setup position. If your arm is straight or your elbow is facing the camera, you know you need to loosen it up.

Mark Blackburn, voted No. 1 by his peers on Golf Digest's 50 Best Teachers in America, has coached dozens of pros, including Justin Rose, Max Homa, Collin Morikawa, Adam Hadwin, Daniel Berger, Charley Hoffman, Alex Fitzpatrick, Matthieu Pavon and Trey Mullinax. His golf academy is located at Greystone Golf & Country Club in Birmingham, Ala.