Multi-piece golf club head

A golf club head, comprising:

• a cup comprising a forward portion of the golf club head, including a hosel, a forward portion of a crown of the golf club head, and a forward portion of a sole of the golf club head, wherein the cup comprises a metal alloy;
• a face plate received in a forward opening of the cup;
• a rear ring formed separately from the cup and coupled to heel and toe portions of the cup to form a club head body, the club head body defining a hollow interior region, a crown opening, and a sole opening, the rear ring comprising a polymeric material and defining a crown-to-skirt transition region;
• a crown insert coupled to the crown opening;
• a sole insert coupled to the sole opening;
• and
• an inertia generator comprising an outwardly extending protrusion formed in the sole of the golf club head and a rear weight positioned at an aft end of the protrusion, the sole insert defining at least a portion of the protrusion of the inertia generator;
• an x-axis extends in a heel-to-toe direction from a heel of the golf club head to a toe of the golf club head, a y-axis extends in a fore-and-aft direction from the face plate to a rear of the golf club head, and a z-axis extends between the crown and the sole perpendicular to the x-axis and the y-axis;
• a center vertical plane is defined in the fore-and-aft direction passing through a center of a rear-facing surface of the inertia generator;
• the center vertical plane passes through a crown-to-skirt transition point on the crown-to-skirt transition region that is the farthest point on the crown-to-skirt transition region from the face plate in the center vertical plane along the y-axis;
• the crown-to-skirt transition point is above a center face location along the z-axis;
• a point on the crown-to-skirt transition region that is 10 mm heelward of the crown-to-skirt transition point as measured along the x-axis is above the center face location along the z-axis;
• and
• a point on the crown-to-skirt transition region that is 10 mm toe-ward of the crown-to-skirt transition point as measured along the x-axis is above the center face location along the z-axis;
• and
• wherein:
• the inertia generator has a lower rear edge where a lower surface of the inertia generator meets the rear-facing surface of the inertia generator;
• the center vertical plane passes through a crown apex point on the crown of the golf club head that is the apex of the crown along the center vertical plane;
• the center vertical plane passes through an inertia generator point on the lower rear edge of the inertia generator;
• a vertical distance D is defined between the crown apex point and the inertia generator point along the z-axis;
• a vertical distance E is defined between the inertia generator point and the crown-to-skirt transition point along the z-axis;
• and
• a vertical distance F is defined between the crown-to-skirt transition point and the crown apex point along the z-axis;
• and
• a ratio
• E
• F
• is 80% to 100%.