by shots hit other than where the center of gravity is located.

There are typically two radii on the face. The first is horizontal bulge, measured in inches of radius from heel to toe. The second is vertical roll, measured in inches of radius from the sole of the club to the topline. Correct amount of bulge or roll is based on the position of the center of gravity of the head. Bulge and roll are not two parameters in which to fit a golfer for, as it is the responsibility of the club designer to determine what radii are best for a particular design.