Patent ID: 7762911

Claim:
A method for predicting velocity, launch angle and/or spin rate of a golf ball following an impact with a golf club or a slug comprising the steps of a. determining at least one pre-impact swing conditions; b. determining at least one property of the golf club; c. calculating a normal force of the impact in a normal direction; d. calculating a transverse force of the impact in a transverse direction; and e. predicting the velocity, launch angle and/or spin rate from steps a-d; wherein the force deformation equation based on Hertzian force deformation equations for step (c) is F = K ⁡ ( ξ a ) β ⁢ ( 1 + A ⁡ ( ξ a ) 2 ) ⁢ ( 1 + α ⁢ ⁢ ξ . a ) wherein ξ=ball deformation, a=ball radius and β ranges from about 1.2 to about 1.5. wherein, the ratio of (ξ) to a is greater than ⅓ and the dampening constant, α, is calculated using the following equation: α = α 1 + α 2 V normal wherein V normal is the initial velocity of relative impact.