Abstract: A designing method according to the present invention includes the steps of: (1) dividing a surface of a phantom sphere of a golf ball 2 into a plurality of units U by division lines 14 obtained by projecting edge lines of a regular polyhedron inscribed in the phantom sphere, on the surface of the phantom sphere; (2) obtaining a base pattern by randomly arranging a plurality of dimples 8 in one unit U such that the dimples 8 do not overlap each other; and (3) developing the base pattern over other units U such that patterns of two adjacent units U are not mirror-symmetrical to each other. The regular polyhedron is preferably a regular dodecahedron or a regular icosahedrons.

Abstract: A cross-sectional shape of each of dimples 8 of a golf ball is a wave-like curve. The wave-like curve has two first projections 16, two second projections 18, two first recesses 20, and two second recesses 22. A circular arc 14 passes through one edge Ed, a deepest point Pd, and another edge Ed. Each first projection 16 is located above the circular arc 14. Each second projection 18 is located above the circular arc 14. Each first recess 20 is located below the circular arc 14. Each second recess 22 is located below the circular arc 14. The ratio of the distance Lp from an edge Ed to a peak Pp to the radius (Di/2) of the dimple 8 is equal to or greater than 20% but equal to or less than 70%.

Abstract: A cross-sectional shape of each of dimples 8 of a golf ball 2 is a wave-like curve. The wave-like curve has two first curves 14, two second curves 16, two third curves 18, and one fourth curve 20. Each first curve 14 and each third curve 18 are upwardly convex. Each second curve 16 and the fourth curve 20 are downwardly convex. Each first curve 14 is connoted to a land 10 at an edge Ed. Each second curve 16 is connected to the first curve 14 at a first inflexion point 22. Each third curve 18 is connected to the second curve 16 at a second inflexion point 24. The fourth curve 20 is connected to the third curves 18 at third inflexion points 26. In the wave-like curve, the upwardly convex curves 14 and 18 and the downwardly convex curves 16 and 20 are alternately arranged.

Abstract: The golf ball 2 has a northern hemisphere N and a southern hemisphere S. The northern hemisphere N is adjacent to the southern hemisphere S across an equatorial line Eq. Each of the northern hemisphere N and the southern hemisphere S has a pole vicinity region 14 and an equator vicinity region 16. Each of the pole vicinity region 14 and the equator vicinity region 16 has a large number of dimples. The dimple pattern of the pole vicinity region 14 includes three units that are rotationally symmetrical to each other about a pole Po. The dimple pattern of the equator vicinity region 16 includes six units that are rotationally symmetrical to each other about the pole Po. The sum (Ps+Pp) of a peak value Ps and a peak value Pp of the golf ball 2 is equal to or greater than 600 mm.

Abstract: On the basis of a surface shape appearing at a predetermined point moment by moment during rotation of a golf ball having numerous dimples on its surface, a data constellation regarding a parameter dependent on a surface shape of the golf ball is calculated. A preferable parameter is a distance between an axis of the rotation and the surface of the golf ball. Another preferable parameter is a volume of space between a surface of a phantom sphere and the surface of the golf ball. Fourier transformation is performed on the data constellation to obtain a transformed data constellation. On the basis of a peak value and an order of a maximum peak of the transformed data constellation, an aerodynamic characteristic of the golf ball is determined. The peak value and the order of the maximum peak are calculated for each of PH rotation and POP rotation.

Abstract: A golf ball 2 has a large number of dimples 8 and a land 10. A rugged pattern is formed on the surface of the golf ball 2 by these dimples 8 and the land 10. These dimples 8 are arranged in a random manner. Each dimple 8 has a crater shape. For designing the rugged pattern, a Cellular Automaton method is used. A fluctuation range Rh of the golf ball 2 that is an index indicating the aerodynamic characteristic during PH rotation is 1.9 mm or less. A fluctuation range Ro of the golf ball 2 that is an index indicating the aerodynamic characteristic during POP rotation is 1.9 mm or less. The absolute value of the difference dR between the fluctuation range Ro and the fluctuation range Rh is 0.4 mm or less.

Abstract: A golf ball 2 has a large number of craters 8. A rugged pattern is formed on the golf ball 2 by the craters 8. A process for designing the rugged pattern includes the steps of: assuming a plurality of states; assuming a large number of cells on a spherical surface; assigning any one of the plurality of states to each cell; assigning, as an attribute, any one of INSIDE, OUTSIDE and BOUNDARY to the each cell based on the state of the each cell and states of a plurality of cells located adjacent to the each cell; assuming craters based on the attributes of the large number of cells; and updating the attribute of the each cell so as to enlarge the areas of the craters, based on the attribute of said each cell and the attributes of the plurality of cells located adjacent to the each cell.

Abstract: A golf ball 2 has numerous craters 8 on its surface. The craters 8 are arranged randomly. Of the surface of the golf ball 2, a part other than the craters 8 is a land 10. By the craters 8 and the land 10, a rugged pattern is formed on the golf ball 2. A process for designing the rugged pattern includes the steps of: (1) assuming a plurality of states; (2) assuming a large number of cells on a spherical surface; (3) deciding an initial state of each cell; (4) determining whether or not to change a state of the each cell based on states of a plurality of cells located adjacent to the each cell; (5) updating the state of the each cell based on the determination; and (6) assigning a land 10 or a recess to the each cell according to the state of the each cell.

Abstract: Based on a surface shape appearing at a predetermined point moment by moment during rotation of a golf ball having numerous dimples on its surface, a data constellation regarding a parameter dependent on a surface shape of the golf ball is calculated. Preferably, the parameter is a distance between an axis of the rotation and the surface of the golf ball. Another preferable parameter is a volume of space between a surface of a phantom sphere and the surface of the golf ball. Based on a maximum value and a minimum value of the data constellation, a fluctuation range is calculated. By dividing the fluctuation range by a total volume of the dimples, an evaluation value is calculated. This value is calculated for each of PH rotation and POP rotation.