A golf club head includes a top portion, a sole portion opposite the top portion, and a striking face configured to impact a golf ball. The striking face includes a face center and a variable thickness distribution such that the club head exhibits an Expected COR value of not less than 0.810, the Expected COR value being determined based on the following relationship Expected ⁢ ⁢ COR = ∑ i = 1 n ⁢ ∑ j = 1 m ⁢ p ij * c ij The variable cij corresponds to an average COR value associated with bin and the variable pij corresponds to a bin-specific impact probability value. And the club head exhibits a characteristic time no greater than 257 microseconds.