Golf club face plate having correlated characteristic time measurement map

A variable thickness face plate for a golf club head, the face plate including a longitudinal axis extending between a toe side and a heel side along a longest length of the face plate, the longitudinal axis dividing the face plate into an upper region and a lower region, the face plate comprising:

• a peripheral edge including an upper peripheral edge and a lower peripheral edge, the upper peripheral edge and the lower peripheral edge being separated by the longitudinal axis, wherein the upper peripheral edge is configured to be adjacent a top of the golf club head when the face plate is installed, and wherein the lower peripheral edge is configured to be adjacent a sole of the golf club head when the face plate is installed;
• and
• a plurality of regions of generally constant thickness extending away from an internal surface of the face plate, the thickness being measured perpendicularly from the internal surface of the face plate, the plurality of regions of generally constant thickness including:
• a first subset of regions of generally constant thickness being disposed along a first generally horizontally-extending path proximate the upper peripheral edge, the first generally horizontally-extending path being disposed radially inward from and parallel to the upper peripheral edge;
• and
• a second subset of regions of generally constant thickness being disposed along a second generally horizontally-extending path proximate the lower peripheral edge, the second generally horizontally-extending path being disposed radially inward from and parallel to the lower peripheral edge,
• wherein each of the plurality of regions of generally constant thickness is enclosed by a boundary edge extending from the internal surface of the face plate,
• wherein an upper portion of the boundary edge of the first subset of regions of generally constant thickness follows a curve that is offset with respect to the upper peripheral edge of the face plate, the curve substantially equally spaced from the upper peripheral edge along its length,
• wherein each of the first and second subsets of regions includes a toeward-most region and a heelward-most region,
• wherein the boundary edge of each toeward-most region includes a toe-facing side,
• wherein the boundary edge of each heelward-most region includes a heel-facing side, and
• wherein at least one of the toe-facing side of the boundary edge of each toeward-most region or the heel-facing side of the boundary edge of each heelward-most region is curved concavely when viewed from the toe or the heel toward a plane extending perpendicular to the longitudinal axis at a center of the face plate, respectively.