Abstract: A putter type golf club head including a heel, toe, ball striking face, upper surface, bottom sole surface and slotted rear portion, including a lower, rearwardly extending flange; and an upper, rearwardly extending flange. The mass of the upper flange is substantially greater than the mass of the lower flange, whereby the club head's center of mass is located toward the upper surface. The upper and lower flanges are formed by a longitudinal slot extending in a heel to toe direction. The upper flange is formed with a semi-circular opening centrally located behind the ball striking face and midway between and separating the heel and toe. The bottom sole of the club head is provided with a bounce angle which raises the leading edge above the putting surface to eliminate scuffing of the club head on the ground during the execution of a putting stroke.