In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover, the intermediate layer is formed into two layers—an inner layer and an outer layer. The surface hardness of the envelope layer-encased sphere, the surface hardness of the inner intermediate layer-encased sphere, the surface hardness of the outer intermediate layer-encased sphere and the surface hardness of the ball together satisfy a specific relationship. This ball has an excellent flight when struck by golfers whose head speeds are not that fast and has a soft yet good feel at impact, thus making it highly suitable for amateur golfers.

In a golf ball having a two-layer core consisting of an inner core layer and an outer core layer, one or more intermediate layer, and a cover serving as an outermost layer, the inner core layer and outer core layer are each formed primarily of a base rubber, the inner core layer has a diameter of at least 19 mm, the intermediate layer and the cover are each formed primarily of a resin material, and the overall core has a specific hardness profile. The golf ball has a high initial velocity while holding down the spin rate on full shots with a driver or long iron, thus enabling a good distance to be achieved. The ball also has a high controllability in the short game.

A golf ball has a core, an inner cover, an outer cover, and dimples. The golf ball satisfies the following mathematical formulas.

Sa=4500+10(A0.5B2Cs)4000

0.04Sa+16020D0.04Sa+160+20 A: a compression (Atti) of the golfball B: a hardness difference (Shore C) between a surface and a center of the core

Cs: (HiTi+2HoTo)/(Ti+2To) D: a total volume (mm.sup.3) of the dimples Hi: a hardness (Shore D) of the inner cover Ho: a hardness (Shore D) of the outer cover Ti: a thickness (mm) of the inner cover To: a thickness (mm) of the outer cover

A golf ball has a core, an inner cover, an outer cover, and dimples, and satisfies the following mathematical formulas.

Vw=54+0.01(2.5AB+5Cv)58.0

0.08X.sup.24.25X+34520D0.08X.sup.24.25X+345+20

A: a compression of the golf ball

B: a hardness difference between a surface and a center of the core

Cv:(HiTi+HoTo)/(Ti+To)

Cs:(HiTi+2HoTo)/(Ti+2To)

D: a total volume of the dimples

X:Sw/Vw

Hi: a hardness of the inner cover

Ho: a hardness of the outer cover

Ti: a thickness of the inner cover

To: a thickness of the outer cover

Sw: 3000+10(AB1.5Cs)

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.

A golf ball dimple pattern based on a square dipyramid, i.e., two square pyramids connected base-to-base, is disclosed. The dimples are arranged within four substantially identical triangular sections on each of two substantially identical hemispheres of the ball.

In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover, the envelope layer is formed into two layersan inner envelope layer and an outer envelope layer. The inner envelope layer-encased sphere, outer envelope layer-encased sphere, intermediate layer-encased sphere and ball have respective surface hardnesses that satisfy a specific relationship. The inner envelope layer or outer envelope layer is formed primarily of one or more thermoplastic elastomer selected from the group consisting of polyester elastomers, polyamide elastomers, polyurethane elastomers, olefin elastomers and styrene elastomers. This ball has an excellent flight when struck by golfers whose head speeds are not that fast and has a good, soft feel at impact, thus making it highly suitable for amateur golfers.

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 is directed to golf balls having improved aerodynamic performance due, at least in part, to the selection of the plan shapes of the dimples thereon. In particular, the present invention is directed to a golf ball that includes at least a portion of its dimples having a plan shape defined by a periodic cosine function mapped along a circular closed path. In addition, the present invention provides methods for designing dimples having a plan shape defined by a periodic cosine function mapped along a circular closed path.

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.