Abstract: A golf ball having a predetermined radius, and a spherical outer surface with a multiplicity of dimples formed therein. A protrusion is formed in each of the dimples which are located in hit portions having a diameter of 5–15 mm, or alternatively, is formed in each of all the dimples. The protrusion has a distal end whose radial distance from the center of the golf ball is equal to the predetermined radius of the golf ball. The protrusion has a partition wall which divides a space in each dimple into a plurality of segmental spaces. The protrusion may have two partition walls which are perpendicular to each other and intersect at right angles for dividing a space in each of the dimples into four segmental spaces.

Abstract: A golf ball having a predetermined radius, and a spherical outer surface with a multiplicity of dimples formed therein. A protrusion is formed in each of the dimples which are located in hit portions having a diameter of 5-15 mm, or alternatively, is formed in each of all the dimples. The protrusion has a distal end whose radial distance from the center of the golf ball is equal to the predetermined radius of the golf ball. The protrusion has a partition wall which divides a space in each dimple into a plurality of segmental spaces. The protrusion may have two partition walls which are perpendicular to each other and intersect at right angles for dividing a space in each of the dimples into four segmental spaces.

Abstract: A golf ball having a predetermined radius, and a spherical outer surface with a multiplicity of dimples formed therein, wherein said spherical outer surface has at least one hit portion which has a diameter of 5-15 mm. The hit portion may be an undimpled portion in which the dimples are absent; a single-dimple portion in which the dimples are absent except a single one of the dimples that is located at a central part thereof; a groove portion in which a plurality of grooves are formed; or an increased contact-area portion in which a protrusion is formed in each dimple.