Face Angle @ Half-Back

What is Face Angle @ Half-Back?

This parameter measures the face angle at the half-back position.  Half-back refers to the position in the backswing when the shaft becomes parallel with the ground for the first time.  Face angle at half-back is measured relative to the vertical, and is 0° when the toe points straight up.  The farther downward the toe points, the more closed the club face. 

What should Face Angle @ Half-Back be?

Different golfers prefer different face angles at half-back.  A good rule of thumb is that the leading edge of your club face should lie parallel to your spine.  This typically reads around 30° to 40° closed at half-back. When you find the angle for each club that results in solid hits, groove that value.