US Patent 8075419 Golf club head with improved mass distribution

A golf club head having a striking wall having a front surface, and a rear surface, a top surface, and a sole portion extending rearwardly from the rear surface, the sole portion having a forward end, a rearward end, an upper surface and a lower surface. The intersection of the upper surface and the rear surface defines an interior sole line. The intersection of the upper surface and the rearward end defines a trailing edge. A region on the upper surface includes variation of the height of the trailing edge or exterior sole line relative to the height of the interior sole.