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(A−0.5B−2Cs)≥4000
0.04Sa+160−20≤D≤0.04Sa+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: (Hi×Ti+2Ho×To)/(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 method for forming a golf ball with a graphene core disclosed herein. The method includes mixing a graphene masterbatch material with a polybutadiene material to form a core mixture, wherein the graphene masterbatch material comprises graphene in an amount from 0.1 to 80.0 weight percent of the graphene masterbatch material mixed with a carrier polymer in an amount from 99.9 to 20 weight percent of the graphene masterbatch material.

Multi-piece golf balls having a multi-layered solid core and multi-layered cover are provided.

A golf ball includes a core, a mid layer, and a cover. An amount of compressive deformation C3 of the golf ball can be not less than 2.80 mm. The golf ball can satisfy the following mathematical formulas (1) and (2):
C1>(124.8−Hs)/11.5  (1)
C2−C1≥(−1/6*C1+(68−H2)/20+(5−Hd)/100)*T2  (2), where C1 is an amount of compressive deformation (mm) of the core, C2 is an amount of compressive deformation (mm) of a sphere including the core and the mid layer, Hd is Hs−Ho, Ho is a hardness (Shore C) of a center the core, Hs is a hardness (Shore C) of a surface of the core, H2 is a hardness (Shore D) of the mid layer, and T2 is a thickness (mm) of the mid layer.

A golf ball 2 includes a core 4, an inner cover 6, and an outer cover 8. The golf ball 2 satisfies the following mathematical formulas (1), (2), and (3):

5≤(Hi*Ti−Dc*Rc)≤40  (1);

5≤(Hi*Ti−Ho*To)≤40  (2); and

−20≤(Ho*To−Dc*Rc)≤20  (3).

Dc is the amount of compressive deformation (mm) of the core 4,

Rc is the radius (mm) of the core 4,

Hi is the Shore C hardness of the inner cover 6,

Ti is the thickness (mm) of the inner cover 6,

Ho is the Shore C hardness of the outer cover 8, and

To is the thickness (mm) of the outer cover 8.

In a golf ball having a two-layer core which includes an inner core layer and an outer core layer and having a cover of one or more layer, the outer core layer is formed of an elastomer composition that includes specific amounts of (A) polybutadiene having a 1,2-bond content of 50 to 95%, (B) a photocurable monomer, oligomer or polymer, and (C) a photopolymerizable initiator. The outer core layer has a thickness of from 1.0 to 4.0 mm, and the two-layer core has a surface hardness on the JIS-C scale of from 75 to 95. The ball is provided with a hardness gradient at the core interior, which lowers the spin rate of the ball, has an improved durability to cracking, and production costs for the outer core layer are kept relatively low.

Multi-layered golf balls having at least one layer made of a foamed silicone composition are provided. Multi-layered golf balls having at least one layer made of non-foamed silicone elastomer composition also are provided. For example, three-piece, four-piece, and five-piece golf balls containing different core and cover structures can be made. The foamed silicones have good thermal stability and durability without sacrificing resiliency. The non-foamed silicone elastomers have high elongation, tensile strength, chemical/fluid-resistance, and weatherability properties. These compositions can be used to form any layer, for example, core, intermediate, or cover, in the golf ball.

A golf ball includes a core, a mid layer, and a cover. A ratio R1 calculated by mathematical formula (1): R1=(Df1−Df2)/(Df2−Df3) is not less than 5.00. A ratio R2 calculated by mathematical formula (2): R2=(T2*H2)/H3 is not less than 2.00. A ratio R3 calculated by mathematical formula (3): R3=D1/T3 is not less than 50. In mathematical formulas (1) to (3), Df1 represents an amount of compressive deformation of the core, Df2 represents an amount of compressive deformation of a sphere including the core and the mid layer, Df3 represents an amount of compressive deformation of the golf ball, T2 represents a thickness of the mid layer, H2 represents a hardness of the mid layer, H3 represents a hardness of the cover, D1 represents a diameter of the core, and T3 represents a thickness of the cover.

A golf ball includes a core, a mid layer, and a cover. A ratio R1 calculated by mathematical formula (1): R1=(Df1−Df2)/(Df2−Df3) is not less than 5.00. A ratio R2 calculated by mathematical formula (2): R2=(T2*H2)/H3 is not less than 2.00. A ratio R3 calculated by mathematical formula (3): R3=D1/T3 is less than 50. In mathematical formulas (1) to (3), Df1 represents an amount of compressive deformation of the core, Df2 represents an amount of compressive deformation of a sphere including the core and the mid layer, Df3 represents an amount of compressive deformation of the golf ball, T2 represents a thickness of the mid layer, H2 represents a hardness of the mid layer, H3 represents a hardness of the cover, D1 represents a diameter of the core, and T3 represents a thickness of the cover.

A system for measuring golf ball trajectory characteristics is disclosed. The system includes artificial grass with a launch location for a golf ball and a plurality of wide-angle distance optical sensors mechanically connected to the artificial grass positioned such that a field of measurement of each wide-angle distance optical sensors intersects. The system also includes a central processing unit connected to the wide-angle distance optical sensors, the central processing unit configured to collect distance measurements from the wide-angle distance optical sensors and to determine a velocity of a trajectory of the golf ball from the launch location to the intersection of the field of measurement of each wide-angle distance optical sensors given a distance between the plurality of the wide-angle distance optical sensors, a distance between the plurality of the wide-angle distance optical sensors and the launch location, and the distance measurements from the plurality of the wide-angle distance optical sensors. Once the velocity of the trajectory of the golf ball is determined, the central processing unit transmits the velocity to a display.