Golf club with coefficient of restitution feature

A golf club head comprising:

• a body having a crown, a sole, a skirt and a face, the face including a geometric center defining a center face location, the body having a center of gravity proximate to the face;
• wherein a reference tangent face plane is defined as a plane tangent to the face at the center face location,
• wherein the center of gravity defines a projection orthogonal to the tangent face plane and passing through the center of gravity such that a projection point is defined at the intersection of the projection and the tangent face plane,
• wherein a reference ground plane is defined along a bottom end of the body, the ground plane thereby being below the golf club head, and
• wherein the projection point is below the center face location;
• wherein the body defines an exterior and an interior bounded by continuous walls on all sides except for a through slot located in the sole proximate to the face, which decouples the face from the sole;
• a plugging material at least partially filling the through slot without interfering with the decoupling of the face from the sole;
• whereby the through slot creates a passage between the exterior and interior if the plugging material is removed;
• further including a forward mass element means located proximate to the face and through slot and having a weight that is about 35 to 50 percent of the total weight of the golf club head.