Understanding and having a correct visual of what needs to happen is critical. The main task of the pelvis is to have it rotate but not have the center move closer to the ball. To accomplish that. On the backswing the trail hip socket has to move farther away from the ball than it started. If it stays in the same position and your pelvis rotates your center has moved closer to the ball. On the down swing the pelvis moves slightly laterally then the lead hip socket moves back to meet the trail hip. So the center of your pelvis moves farther away from the ball. This actually accelerates the club and the club head. Task is for the pelvis to maintain or to move farther away from the ball that it was at address.