I have created what could be referred to as a waterline at the ground and colored the portion of the club that would be under water or below the ground plane.
The second part of this video illustrates the bowing of the club and the need for the proper shaft flex as it relates to swing speed. Because the toe of the club has weight, as centripetal force pulls the toe of the club outward it bows the shaft upward, flattening the lie of the club. When Cam addresses the ball the toe of the club is up in the air but at impact, with the shaft bowed, the toe club is level or flat.
This happens with irons as well, if not more because they have more weight at the toe.
This is why a flat or square shaft would never work in golf. The properties of a round shaft work like a universal joint where torque or bend in one direction can be retained while the shaft is rotating. At the top of the downswing the shaft stores torque in what would be vertically bending the toe of club upward and then delivers that same torque sideways to the ball because the shaft has rotated but the torque remained in its original direction.
