Golf club head

1. A golf club head comprising: a shaft hole; a face surface; a sole surface; and a leading edge, wherein

the sole surface includes a first sole region; an outer edge of the first sole region includes a first edge line, a second edge line, a third edge line, and a fourth edge line; the first edge line is inclined so as to come closer to the face surface toward a toe side; the second edge line is inclined so as to come closer to the face surface toward a heel side; the third edge line is inclined so as to come closer to the face surface toward the heel side; the fourth edge line is inclined so as to come closer to the face surface toward the toe side;

a back side end of the first edge line and a back side end of the second edge line are joined via a connecting point A;

a face side end of the first edge line and a back side end of the third edge line are joined via a connecting point B, wherein point B and a point D are located at opposite ends of the third edge line;

a face side end of the second edge line and a back side end of the fourth edge line are joined via a connecting point C, wherein point C and a point E are located at opposite ends of the fourth edge line;

a distance between points D and E is less than a difference between points B and C;

the connecting point B is located on the toe side with respect to a face center;

the connecting point C is located on the heel side with respect to the face center;

an outer surface of the first sole region has a projecting curve on a section including the connecting point B and the connecting point C;

the outer surface of the first sole region has a projecting curve on a section including the connecting point A and the face center; and

when a state where a center axial line of the shaft hole is included in a plane perpendicular to a level surface and the head is placed at a predetermined lie angle and real loft angle on the level surface is defined as a base state, the first sole region is brought into contact with the level surface in the base state.

2. The golf club head according to claim 1 , wherein the sole surface further includes:

a second sole region located on the toe side with respect to a face side end point D of the third edge line; a third sole region located on the heel side with respect to a face side end point E of the fourth edge line; a fifth edge line extending on the toe side from the end point D, and a sixth edge line extending on the heel side from the end point E;

the second sole region and the third sole region smoothly continue toward a back side from the leading edge;

the second sole region is located between the fifth edge line and the leading edge; and

the third sole region is located between the sixth edge line and the leading edge.

3. The golf club head according to claim 1 , wherein the sole surface further includes a front sole region; and

the front sole region forms a continuous surface smoothly joining the leading edge and the first sole region.

4. The golf club head according to claim 2 , wherein the sole surface further includes a front sole region;

the front sole region forms a continuous surface smoothly joining the leading edge and the first sole region; and

the front sole region forms a continuous surface smoothly joining the second sole region and the third sole region.

5. The golf club head according to claim 1 ,

wherein a face member and the remainder including one or more members are welded to each other; and

if a welding position of the face member and the remainder on the face surface is defined as Pk, a distance between the welding position Pk and a face side end point E of the fourth edge line in a toe-heel direction is equal to or less than 10 mm.

6. The golf club head according to claim 5 , wherein the remainder is a head body;

and the welding position Pk is a position of a heel side end of the face member on the face surface.