Jack did it by lifting his left heel on his backswing. You may think of this move as “new school,” but if you look back at Jack Nicklaus, you’ll find the old-school equivalent of how to leverage the ground for speed and power. It was amazing - a perfect downswing sequence employing max ground forces. From this vantage point, I saw just how forcefully he was pushing his front foot into the ground.

I remember filming him on the range, flat on the ground directly in front of him on his target line. He was hitting balls in shorts and a T-shirt. This generates a ton of clubhead speed, especially for a guy Rory’s size (five foot nine inches, 160 pounds). Rory unwinds his hips extremely late in his downswing, because of the immense force he puts into the ground with his legs as he starts down. But it was the source of his hip speed that fascinated me. After testing him using 3D, we found that he had the fastest hips we’d ever seen. My first impression watching Rory’s swing was his effortless power. My friend Padraig Harrington warned me: “This kid’s going to change the world.” He was right. I first met Rory McIlroy at the Titleist Performance Institute when he was just 18 years old. Rory McIlroy remains one of the most impressive drivers of the ball in the game today.

Jack hamm golf swing slow motion