Golf club

1. An iron-type golf club head comprising:

a body comprising a heel portion, a toe portion, a face portion, a sole portion, and a top-line portion, the body having a volume less than 120 cc;

wherein the sole portion extends rearwardly proximate to a lower end of the face portion, the toe portion extends rearwardly proximate to a toe end of the face portion, and the top-line portion extends rearwardly proximate to an upper end of the face portion;

wherein the face portion includes an ideal striking location that defines an origin of a coordinate system in which an x-axis is tangential to the face portion at the ideal striking location and is parallel to a ground plane when the body is in a normal address position, a y-axis extends perpendicular to the x-axis and is also parallel to the ground plane, and a z-axis extends perpendicular to the ground plane, wherein a positive x-axis extends toward the heel portion from the origin, a positive y-axis extends rearwardly from the origin, and a positive z-axis extends upwardly from the origin;

wherein the sole portion comprises two or more slots extending upwardly in the z-axis direction into the body and extending through an entire thickness of the sole portion into an open cavity behind the face portion, wherein the two or more slots are configured to provide a maximum characteristic time (CT) proximate to the ideal striking location and to increase CT at non-ideal striking locations proximate the toe portion and the sole portion; and

wherein a damper is included in the open cavity of the golf club head and attached to a rear surface of the face portion.

2. The iron-type golf club head of claim 1 , wherein the two or more slots in the sole portion comprise a first slot and a second slot, wherein the second slot is rearward of the first slot.

3. The iron-type golf club head of claim 1 , wherein the two or more slots in the sole portion comprise two slots that are aligned in a row extending in a heel-to-toe direction.

4. The iron-type golf club head of claim 1 , wherein the two or more slots in the sole portion comprise three slots that are aligned in a row extending in a heel-to-toe direction.

5. The iron-type golf club head of claim 1 , wherein the two or more slots in the sole portion comprise a row of two or more aligned slots extending in a heel-to-to direction and one or more slots rearward of the row.

6. The iron-type golf club head of claim 1 , further comprising a slot in the toe portion.

7. The iron-type golf club head of claim 1 , further comprising a slot in the top-line portion.

8. The iron-type golf club head of claim 1 , further comprising:

a slot in the toe portion; and

a slot in the top-line portion,

wherein the two or more slots in the sole portion comprise four or more slots in the sole portion,

wherein at least one point on the face portion having an x-axis coordinate of −30 mm has a contact time that is at most 130 microseconds less than a contact time at the ideal striking location.

9. The cavity-back or hollow iron-type golf club head of claim 1 , wherein the damper comprises a non-metallic material.

10. The cavity-back or hollow iron-type golf club head of claim 1 , wherein a balance point of the golf club head on the face portion has a characteristic time (CT) of no less than 248 microseconds.

11. An iron-type golf club head comprising:

a body comprising a heel portion, a toe portion, a face portion, a sole portion, and a top-line portion, the body having a volume less than 120 cc;

wherein the sole portion extends rearwardly proximate to a lower end of the face portion, the toe portion extends rearwardly proximate to a toe end of the face portion, and the top-line portion extends rearwardly proximate to an upper end of the face portion,

wherein the face portion includes an ideal striking location that defines an origin of a coordinate system in which an x-axis is tangential to the face portion at the ideal striking location and is parallel to a ground plane when the body is in a normal address position, a y-axis extends perpendicular to the x-axis and is also parallel to the ground plane, and a z-axis extends perpendicular to the ground plane, wherein a positive x-axis extends toward the heel portion from the origin, a positive y-axis extends rearwardly from the origin, and a positive z-axis extends upwardly from the origin;

wherein the sole portion comprises one or more slots extending through an entire thickness of the sole portion into an open cavity behind the face portion; and

wherein the toe portion comprises one or more slots extending heelwardly in the x-axis direction into the body and extending through an entire thickness of the toe portion into the open cavity behind the face portion,

wherein the slots in the toe and sole portions are configured to provide a maximum characteristic time (CT) proximate to the ideal striking location and to increase CT at non-ideal striking locations proximate the toe portion and the sole portion.

12. The iron-type golf club head of claim 11 , wherein the one or more slots in the toe portion extend through the toe region into a cavity or a recess of the body.

13. The iron-type golf club head of claim 11 , wherein the one or more slots in the toe portion are parallel to an edge of a striking face of the face portion.

14. The iron-type golf club head of claim 11 , further comprising a slot in the top-line portion.

15. The iron-type golf club head of claim 11 , further comprising a slot extending from the sole portion to the toe portion.

16. The iron-type golf club head of claim 11 , wherein at least one point on the face portion having an x-axis coordinate of −30 mm has a contact time that is at most 130 microseconds less than a contact time at the ideal striking location.

17. A cavity-back or hollow iron-type golf club head comprising:

a body comprising a heel portion, a sole portion, a toe portion, a face portion, and a top-line portion,

wherein the sole portion extends rearwardly proximate to a lower end of the face portion, the toe portion extends rearwardly proximate to a toe end of the face portion, and the top-line portion extends rearwardly proximate to an upper end of the face portion,

wherein the face portion includes an ideal striking location that defines an origin of a coordinate system in which an x-axis is tangential to the face portion at the ideal striking location and is parallel to a ground plane when the body is in a normal address position, a y-axis extends perpendicular to the x-axis and is also parallel to the ground plane, and a z-axis extends perpendicular to the ground plane, wherein a positive x-axis extends toward the heel portion from the origin, a positive y-axis extends rearwardly from the origin, and a positive z-axis extends upwardly from the origin;

two or more slots in the sole portion extending through an entire thickness of the sole portion into an open cavity behind the face portion;

one or more slots in toe portion extending through an entire thickness of the toe portion into the open cavity behind the face portion; and

one or more slots in the top-line portion extending through an entire thickness of the topline portion into the open cavity behind the face portion,

wherein the slots in the sole, toe, and top-line portions are configured to provide a maximum characteristic time (CT) proximate to the ideal striking location and to increase CT at a non-ideal striking location proximate the toe portion.

18. The cavity-back or hollow iron-type golf club head of claim 17 , further comprising a slot extending from the sole portion around to the toe portion.

19. The cavity-back or hollow iron-type golf club head of claim 17 , further comprising a filler material within one or more of the slots.

20. The cavity-back or hollow iron-type golf club head of claim 17 , wherein at least one point on the face portion having an x-axis coordinate of −30 mm has a contact time that is at most 130 microseconds less than a contact time at the ideal striking location.