A hollow golf club head with a concave portion is disclosed and claimed.
The club head includes a metallic portion and a light-weight portion,
which may be formed of plastic, composite, or the like. The concave
portion allows the club designer to make a club head having very thin
portions while still maintaining the requisite structural integrity.
Convex bulges may optionally be provided to house weight inserts to
enhance the playing characteristics of the golf club. The metallic
portion of the club head may take on the appearance of a frame, into
which several light-weight inserts are positioned. These light-weight
inserts may be positioned in the crown, skirt, and sole of the club head.