Let the lead heel and knee release for more turn
The guest coach describes allowing his left heel and left knee to release a little in the backswing rather than keeping the heel planted, which increases his end range of motion while he still maintains his anchor point and does not move far off the ball. He credits this change with about 20 yards and picking up a couple of miles per hour of club speed.
Channel: PorzakGolf
Watch official source at 0:55Why this context matters
The guest coach is describing a change to his own swing.