Berger previously dealt with back issues that stemmed from his arched lower back at address. Now he bends more from his pelvis, creating a flatter lower back.

Berger used to turn his shoulders too flat on the backswing, which caused the clubhead to get inside early. Blackburn got his left shoulder working more down going back, steepening his turn.

Notice how Berger's left shoulder is now working under his chin—proof of a steeper turn. As a result, his arms are more in front of him and tracking toward a higher plane at the top of the swing.

Berger's left arm covers his trail shoulder. This higher position, paired with a more complete turn behind the ball, has helped Berger get rid of his back pain.

Berger used to slide too much to the left in the downswing, Blackburn says. That caused his upper body to hang back, leading to back pain. Now, Berger feels like he posts on his left leg rather than sliding laterally, which helps him hit a consistent fade off the tee.

Notice how Berger's clubhead is perfectly in line with his hands—this is an on-plane delivery position. Berger's hips have cleared out of the way and his left leg is starting to straighten.

Berger is able to hit low-spin bullets off the tee because he has a very neutral attack angle with the driver. Rather than chopping down on the ball or hanging back and hitting way up, Berger covers the ball.

Berger's club is moving around to the left with the rotation of his body, allowing him to hit a reliable fade. His shoulders are rotating on plane—there's no hanging back move which caused the back issues.

An in-balance finish position with his upper body stacked over his lower body—proof that he's covered the golf ball. Berger's swing upgrades with Blackburn have him swinging pain-free.