A golf ball has a plurality of dimples 12 and a land 14 on a surface thereof. The golf ball further has a large number of minute projections 18 formed on surfaces of the dimples 12 and the land 14. The surface of the golf ball has an arithmetic average height Sa of not less than 0.5 m and not greater than 30 m. An average value Hav of heights H of the minute projections 18 is not less than 0.5 m and not greater than 50 m. A ratio Pp of a sum of areas of all the minute projections 18 to a surface area of a phantom sphere of the golf ball is not less than 7%. An average value Dav of diameters D of the minute projections 18 is not less than 5 m and not greater than 50 m.

In a golf ball having a core, an intermediate layer and a cover, the intermediate layer-encased sphere has a higher surface hardness than the ball. The core hardness profile in the ball is designed such that the core surface has a Shore C hardness value which is at least 27 higher than the Shore C hardness value at the core center, and the surface areas A to F calculated from hardness differences between positions located at specific distances in the core and differences between the specific distances satisfy a specific formula. This golf ball has an excellent flight performance when struck by skilled amateur golfers and professionals, and also has a good controllability on shots with an iron.

The present invention provides a method for arranging dimples on a golf ball surface in which the dimples are arranged in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing or eliminating great circles due to parting lines.

A golf ball having a core and a cover that is formed of a resin composition which includes (A) a polyurethane or a polyurea and (B) a styrenic resin material, when dropped from a height of 3 m and made to collide with a metal plate, has velocities 200 ms before and 200 ms after contact that satisfy the condition: (incident velocity)(rebound velocity)0.80 m/s. The ball has a good controllability on approach shots without a loss in the distance achieved on shots with a driver, and thus is particularly useful to professional golfers and skilled amateurs.

In a golf ball having a two-layer core consisting of an inner core layer and an outer core layer, an intermediate layer consisting of at least one layer and a cover of one or more layer, the inner core layer and outer core layer are each formed of a rubber composition made up primarily of a base rubber, the inner core layer has a diameter of not more than 30 mm; and the core has specific hardness ratios (JIS-C hardness/Shore D hardness) at specific points on the cross-section thereof and the surface and center of the two-layer core has a specific hardness difference. This golf ball has a reduced spin rate on full shots with a driver and middle irons, thus imparting an excellent flight performance, and moreover has a good controllability in the short game on approach shots, making it ideal as a golf ball for professional golfers and mid- and high-level amateur golfers.

Golf balls including at least one modified dimple group are disclosed. The modified dimple group comprises one or more modified dimples forming an axially symmetric pattern about a Correction Area Centroid located on an axis of symmetry at a latitude greater than 0, where 0 represents the hemispherical pole and 90 represents the equator. The modified dimples can be altered, for example, by changing dimple coverage, dimple diameter, dimple depth, dimple edge angle, dimple volume, dimple cross-sectional shape, and/or dimple plan shape. Optionally, the dimples have a catenary cross-sectional shape and the modified dimples are altered by changing the shape factor and/or chord depth. Such modifications preferably produce a golf ball that flies more consistently regardless of orientation when struck than a corresponding golf ball without such modifications.

The present invention provides golf balls having a pattern of stellated polygon shaped dimples and grooves with pre-selected and coordinated color appearances on the outer surface of the ball to produce a unique and desirable overall golf ball color appearance.

A golf ball has a large number of exposed portions 22 on a surface thereof. An average value Hav of heights H of these exposed portions 22 is not less than 0.5 m and not greater than 50 m. The surface of the golf ball has one or more first zones and one or more second zones. An average value Hav1 of the heights H of the exposed portions 22 on these first zones is higher than an average value Hav2 of the heights H of the exposed portions 22 on these second zones. Preferably, the average value Hav1 and the average value Hav2 satisfy the following mathematical formula.
3(Hav1Hav2)50

A golf ball has a plurality of dimples 12 and a land 14 on a surface thereof. The golf ball further has a large number of minute projections 18 formed on surfaces of the dimples 12 and the land 14. An average depth Fav of the dimples 12 and an average height Hav of the minute projections satisfy the following mathematical formula (1).
Hav/Fav0.050(1)
A ratio M (%) of a sum of areas of all the dimples 12 relative to a surface area of a phantom sphere of the golf ball and an average value Pav (m) of pitches P each between a minute projection 18 and another minute projection 18 adjacent to this minute projection 18 satisfy the following mathematical formula (2).
M/Pav>0.3(2)

The present invention is a golf ball which comprises cat-witch dimples on the surface thereof. The cat-witch dimples have a cross-sectional shape defined by the superposition of a catenary curve function and a Witch of Agnesi curve function. The cat-witch dimples include a plurality of similarly shaped cat-witch dimples having at least two different dimple diameters.