At impact we can use a tangent(1) of the circular clubhead swing path to create our second vector of the D Plane. A ball struck before the clubhead’s lowest point, with an on-plane swing will have the clubhead traveling in three particular dimensions at impact. Those dimensions are: forwards (towards the target), downwards (towards the ground), and outwards (away from yourself).

This is where ball placement becomes very important. The exact same swing can produce vastly different ball flights depending on the ball’s location at impact. If we were to place the ball directly at the club’s lowest point on the swing, there would no longer be any downwards dimension, nor would there be any outwards dimension. The swing path’s tangent at that point would be a horizontal line, pointing directly at the target. The further away from the swing’s lowest point we place the ball, the less the tangent points forwards, and the more it points downwards and outwards.