Golf club heads are provided for selectively increasing or optimizing the coefficient of restitution (COR) at likely impact locations on the striking face of the golf club heads, while simultaneously maintaining characteristic time (CT) below a threshold value in those likely impact locations. By analyzing historical impact locations of a large cross-section of golfers, golf club head COR values can be increased or optimized in preferential locations on the striking face, such as using weighting factors for a predefined set of locations on the striking face. Therefore, instead of increasing COR uniformly across the face and/or increasing COR at impact locations on the face where golfers are unlikely to strike the golf ball, the sweet spot of the golf club head can be increased at the impact locations where golfers typically strike the golf ball.