In order to satisfy at a high level the golf ball flight and control performances relied on by professional golfers and skilled amateurs, this invention provides a multi-piece solid golf ball G having a core 1, a cover 3 and an intermediate layer 2 therebetween wherein the core is formed of a rubber composition that includes an alcohol having a value obtained by dividing the molecular weight of the alcohol by the number of hydroxyl groups thereon which is 70 or less. Also, letting Hc be the JIS-C hardness at the center of the core, H12 be the JIS-C hardness at a position 12 mm from the core center and Ho be the JIS-C hardness at the surface of the core, the core has a hardness profile in which these hardnesses satisfy fixed relationships defined by specific formulas.

A golf ball includes a core and a cover. The core is formed of a material molded under heat from a rubber composition. The rubber composition includes components (A) through (C). The components (A) through (C) are (A) a base rubber, (B) an organic peroxide, and (C) a metal salt containing hydration water.

A rubber composition for golf balls includes (a) a base rubber, (b) a co-crosslinking agent which is an α,β-unsaturated carboxylic acid and/or a metal salt thereof, (c) a crosslinking initiator, and (d) a lower alcohol having a molecular weight of less than 200. When the rubber composition is used in a golf ball having a core and a cover of one or more layers encasing the core, by setting the hardness difference in the core interior hardness profile to a large value while maintaining a desired core hardness, low spin properties can be manifested on golf ball shots, enabling the flight performance of the ball to be improved.

An object of the present invention is to provide a golf ball having excellent approach spin performance under a dry condition and excellent approach spin performance under a condition that there is grass between the golf ball and the club face. The present invention provides a golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein the paint film is composed of at least one layer, and an outermost paint film layer located at the outermost layer of the golf ball contains, as a base resin, a polyurethane obtained by a reaction between (A) a polyisocyanate composition and (B) a polyol composition, (B) the polyol composition contains a urethane polyol as a polyol component, and the outermost paint film layer has a dynamic friction coefficient of from 0.65 to 1.2 measured with a dynamic friction tester under specific conditions.

A rubber composition for golf balls includes (a) a base rubber, (b) a co-crosslinking agent which is an α,β-unsaturated carboxylic acid and/or a metal salt thereof, (c) an organic peroxide, (d) water or an alcohol, and (e) an antioxidant which is a benzoimidazole of the following general formula and/or a metal salt thereof. When the rubber composition is used in constituent members of a golf ball, especially the core, the golf ball exhibits low spin properties on shots, resulting in an improved flight performance and enabling a good durability to be maintained.

Provided is a data processing system configured for golf ball tracking, comprising: a host computing system; a display in communication with the host computing system; one or more smart golf balls, each comprising a Real Time Location System (RTLS) Ultra-wideband (UWB) transmitter/receiver and a corresponding ID, in communication with the host computing system; three or more beacons, each comprising an RF transmitter/receiver, in communication with the host computing system; and a golf ball tracking module.

In a golf ball having a cover layer that is formed of a resin material composed primarily of polyurethane or polyurea, the cover layer includes a colored surface portion having a visible light transmittance of at least 0.6%. A method for producing the golf ball includes the steps of forming the cover layer over a core or other target sphere and providing the colored surface portion by coloring the surface of the cover layer. The cover layer which includes the colored surface portion has a visible light transmittance of at least 0.6%. The golf ball has a surface with a distinctive aesthetic appearance and retains both a good spin performance and a good scuff resistance, making it useful as a ball for professional and skilled amateur golfers.

The golf ball 1 includes a surface having multiple dimples thereon. When a lift coefficient measured under conditions with a Reynolds number of 80000 and a spin rate of 2000 rpm is CL1, and when a lift coefficient measured under conditions with a Reynolds number of 70000 and a spin rate of 1900 rpm is CL2, CL1 and CL2 satisfy 0.990≤CL2/CL1.

A golf ball composed of a core and a cover has a spin rate and a launch angle on approach shots at a head speed (HS) of 20 m/s or 10 m/s that satisfy formulas (1) and (2) below:

Spin W/Spin D≥0.70   (1)

Ang W/Ang D<1.20   (2)

Here, Spin D is the spin rate (rpm) under dry conditions, Spin W is the spin rate (rpm) under wet conditions, Ang W is the launch angle (°) under wet conditions and Ang D is the launch angle (°) under dry conditions. The golf ball suppresses a decrease in the spin rate on approach shots in rainy weather and thus has an improved controllability, making it especially useful to professional golfers and skilled amateurs who desire a high spin performance around the green.

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 layers—an 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 hardness that satisfy a specific relationship. The inner envelope layer or outer envelope layer is formed primarily of one or more elastomer, and further the core has a particular hardness profile. 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,