Golf club head

1. A golf club head comprising:

a body having a bottom portion, a top portion, a front portion, and a back portion, defining a volume of at least about 400 cm 3 , and a front-rear dimension of at least about 111 mm;

a sole located on the bottom portion and a face positioned at the front portion;

wherein the golf club head has a head origin defined as a position on a face plane at a geometric center of the face, the head origin including an x-axis tangential to the face and generally parallel to the ground when the head is in an address position where a positive x-axis extends towards a heel portion and a negative x-axis extends towards a toe portion, a y-axis extending perpendicular to the x-axis and generally parallel to the ground when the head is in the address position where a positive y-axis extends from the face and through a rearward portion of the body, and a z-axis extending perpendicular to the ground, to the x-axis and to the y-axis when the head is in the address position where a positive z-axis extends from the head origin and generally upward, thereby defining a Y-Z plane including the y-axis and the z-axis wherein the golf club head has a center of gravity with an x-axis coordinate, a y-axis coordinate less than about 50 mm, and a z-axis coordinate less than about 2 mm;

a groove located in the sole and extending from the heel portion to the toe portion, the groove having a toe edge, a heel edge, a leading edge located toward the face and connecting a portion of the toe edge and the heel edge, a trailing edge opposite the leading edge and connecting a portion of the toe edge and the heel edge, an X-direction groove width that is greater than the center of gravity y-axis coordinate, and a Y-direction groove length that is less than the X-direction groove width, wherein a portion of the leading edge is curved and a portion of the trailing edge is curved, and within a vertical plane parallel to the Y-Z plane an exterior surface of the groove transitions from an initial convex contour at the leading edge to a concave contour between the leading edge and the trailing edge;

wherein the golf club head has a moment of inertia about the center of gravity z-axis, I CGz , of at least about 450 kg·mm 2 ; and

wherein the golf club head has a coefficient of restitution greater than about 0.810.

2. The golf club head of claim 1 , wherein the x-axis coordinate is between about −2 mm and about 7 mm, the y-axis coordinate is at least about 30 mm, and the z-axis coordinate is greater than about −7 mm.

3. The golf club head of claim 2 , wherein a portion of the groove has a groove depth of at least 6 mm.

4. The golf club head of claim 3 , wherein the moment of inertia about the center of gravity z-axis, I CGz , is at least about 500 kg·mm 2 .

5. The golf club head of claim 4 , wherein the golf club head has a moment of inertia about the center of gravity x-axis, I CGx , of at least about 300 kg·mm 2 .

6. The golf club head of claim 3 , wherein the groove has a groove volume of at least about 10 cm 3 .

7. The golf club head of claim 2 , wherein the center of gravity is at least 15 mm aft of a hosel axis.

8. The golf club head of claim 2 , further comprising a weight port located on the sole.

9. The golf club head of claim 8 , wherein the weight port is located near the back portion of the golf club head.

10. The golf club head of claim 9 , wherein the center of gravity is located toe-ward of a center of the weight port.

11. The golf club head of claim 1 , wherein the X-direction groove width is at least 100 mm.

12. The golf club head of claim 1 , wherein at least a portion of the top portion is formed of a composite material and the face has a variable face thickness.

13. The golf club head of claim 1 , further including (a) two or more indentations located on the sole below the top portion silhouette profile, the two or more indentations being defined in part by a wall that extends inwardly from a surface of the sole and into the body, and (b) a plateau located on the sole, wherein the two or more indentations comprising one or more toe-side indentations located at least partially toe-ward of the plateau and one or more heel-side indentations located at least partially heel-ward of the plateau, the toe-side indentation includes a toe-side curved edge having a portion that follows the top portion silhouette profile, and the heel-side indentation includes a heel-side curved edge having a portion that follows the top portion silhouette profile.

14. The golf club head of claim 13 , further comprising a weight port located on the plateau.

15. The golf club head of claim 14 , wherein the center of gravity is located toe-ward of a center of the weight port.

16. The golf club head of claim 13 , wherein the two or more indentations have a combined volume that is at least 9 cm 3 .

17. The golf club head of claim 1 , further including a concave depression located on the sole.

18. A golf club head comprising:

a body having a bottom portion, a top portion, a front portion, and a back portion, defining a volume of at least about 400 cm 3 , a front-rear dimension of at least about 111 mm, and at least a portion of the top portion is formed of a composite material;

a sole located on the bottom portion and a face positioned at the front portion, wherein a portion of the face is formed of composite material and has a variable face thickness;

wherein the golf club head has a head origin defined as a position on a face plane at a geometric center of the face, the head origin including an x-axis tangential to the face and generally parallel to the ground when the head is in an address position where a positive x-axis extends towards a heel portion and a negative x-axis extends towards a toe portion, a y-axis extending perpendicular to the x-axis and generally parallel to the ground when the head is in the address position where a positive y-axis extends from the face and through a rearward portion of the body, and a z-axis extending perpendicular to the ground, to the x-axis and to the y-axis when the head is in the address position where a positive z-axis extends from the head origin and generally upward, wherein the golf club head has a center of gravity with an x-axis coordinate between about −2 mm and about 7 mm, a y-axis coordinate is at least about 30 mm, and a z-axis coordinate less than about 2 mm and greater than about −7 mm;

a groove located in the sole and extending from the heel portion to the toe portion, the groove having a toe edge, a heel edge, a leading edge located toward the face and connecting a portion of the toe edge and the heel edge, a trailing edge opposite the leading edge and connecting a portion of the toe edge and the heel edge, an X-direction groove width that is greater than the center of gravity y-axis coordinate, and a Y-direction groove length that is less than the X-direction groove width, wherein a portion of the leading edge is curved and a portion of the trailing edge is curved;

wherein the golf club head has a moment of inertia about the center of gravity z-axis, I CGz , of at least about 450 kg·mm 2 , and a moment of inertia about the center of gravity x-axis, I CGx , of at least about 300 kg·mm 2 ; and

wherein the golf club head has a coefficient of restitution greater than about 0.810.

19. The golf club head of claim 18 , wherein a portion of the groove has a groove depth of at least 6 mm.

20. The golf club head of claim 18 , wherein the moment of inertia about the center of gravity z-axis, I CGz , is at least about 500 kg·mm 2 , and the center of gravity is at least 15 mm aft of a hosel axis.