A golf ball 2 includes a core 4 , a mid layer 6 positioned outside this core, and a cover 8 positioned outside this mid layer. When a total thickness of the mid layer 6 and the cover 8 is denoted by L (mm), a Shore C hardness at a point A away from a surface of the core 4 toward a central point of the core 4 by 5L (mm) is denoted by Ha, a Shore C hardness at a point B away from the surface of the core 4 toward the central point of the core 4 by 2.5L (mm) is denoted by Hb, and a Shore C hardness at the central point of the core 4 and Shore C hardnesses of the mid layer 6 and the cover 8 are denoted by H0, Hm, and Hc, respectively; the golf ball 2 satisfies Hc−Hb>0, Hm−H0>0, and Ha−Hm>0.
1. A golf ball comprising a core, a mid layer positioned outside the core, and a cover positioned outside the mid layer, wherein
when a total thickness of the mid layer and the cover is denoted by L (mm), a Shore C hardness at a point A away from a surface of the core toward a central point of the core by 5L (mm) is denoted by Ha, a Shore C hardness at a point B away from the surface of the core toward the central point of the core by 2.5L (mm) is denoted by Hb, a Shore C hardness at the central point of the core is denoted by H0, a Shore C hardness of the mid layer is denoted by Hm, and a Shore C hardness of the cover is denoted by Hc,
the golf ball satisfies the following formulas (1) to (3):
Hc−Hb≥ 17 (1),
Hm−H 0>0 (2),
Ha−Hm> 0 (3),
an amount of compressive deformation Sf of the golf ball is not less than 3.66 mm,
a difference (Hb−Ha) between the hardness Hb and the hardness Ha is not less than 10, and
the hardness Hm is greater than 40 and not greater than 57.
2. The golf ball according to claim 1 , wherein
the mid layer is formed of a plurality of layers, and
the hardness Hm is a Shore C hardness of a most flexible layer among the plurality of layers forming the mid layer.
3. The golf ball according to claim 1 , wherein a difference (Hc−Hb) between the hardness Hc and the hardness Hb is not less 17 and less than 40.
4. The golf ball according to claim 1 , wherein a difference (Hm−H0) between the hardness Hm and the hardness H0 is not less than 1 and not greater than 20.
5. The golf ball according to claim 1 , wherein a difference (Ha−Hm) between the hardness Ha and the hardness Hm is not less than 1 and not greater than 15.
6. The golf ball according to claim 1 , wherein a difference (Hs−H0) between a Shore C hardness Hs at the surface of the core and the hardness H0 is not less than 20 and not greater than 40.
7. The golf ball according to claim 1 , wherein a difference (Hc−Hm) between the hardness Hc and the hardness Hm is greater than 25 and less than 50.
8. The golf ball according to claim 1 , wherein a difference (Hb−Hm) between the hardness Hb and the hardness Hm is greater than 5 and less than 25.
9. The golf ball according to claim 1 , wherein a difference (Hb−Ha) between the hardness Hb and the hardness Ha is not less than 10 and less than 15.
10. The golf ball according to claim 1 , wherein a difference (Ha−H0) between the hardness Ha and the hardness H0 is greater than 5 and less than 18.
11. The golf ball according to claim 1 , wherein a difference (Hb−H0) between the hardness Fib and the hardness H0 is greater than 12 and less than 30.
12. The golf ball according to claim 1 , wherein the total thickness L is not greater than 3.2 mm.
13. The golf ball according to claim 1 , wherein
the mid layer is formed of a plurality of layers, and
the hardness Hc is greater than a Shore C hardness of a hardest layer among the plurality of layers forming the mid layer.
14. The golf ball according to claim 1 , wherein
the core has a diameter of not less than 36.0 mm and not greater than 41.0 mm.
15. The golf ball according to claim 1 , wherein
the Shore C hardness Ha is not less than 45 and not greater than 78.
16. The golf ball according to claim 1 , wherein
the Shore C hardness Hb is not less than 55 and not greater than 85.
17. The golf ball according to claim 1 , wherein
the hardness Hc is not less than 76 and not greater than 97.