A base polymer of a cover 3 of a golf ball 1 includes a thermoplastic
polyurethane elastomer as a principal component. Dimples 6 are formed on
the surface of the cover 3. A proportion R1 of number of dimples
6 having a ratio (B/T), which is a ratio of a height B of a bottom of the
dimple 6 to a nominal thickness T of the cover 3, of equal to or
less than 0.70 occupied in total number of the dimples is equal to or greater than
10%. A proportion R2 of number of dimples 6 having the ratio (B/T)
of less than 0.30 occupied in total number of the dimples is equal to or less than
10%. A mean value of the ratio (B/T) for all the dimples 6 is equal to or
less than 0.86. The golf ball 1 includes a mid layer 5 having Shore
D hardness of equal to or greater than 55. Difference (Hm-;Hc) between Shore D
hardness Hm of the mid layer 5 and Shore D hardness Hc of the cover 3
is equal to or greater than 5.
