Golf is a ball sport in which competing golfers use many types of clubs to hit balls into a series of holes on a course using the fewest number of strokes. The golfer with the least number of strokes by the end of the game wins.
The United States Golf Association includes rules for golf balls in Appendix II of their Rules for Golf.
The ball must not be substantially different from the traditional and customary form and make. The material and construction of the ball must not be contrary to the purpose and intent of the Rules.
The weight of the ball must not be greater than 1.620 ounces avoirdupois (45.93 gm).
The diameter of the ball must not be less than 1.680 inches (42.67 mm). This specification will be satisfied if, under its own weight, a ball falls through a 1.680 inches diameter ring gauge in fewer than 25 out of 100 randomly selected positions, the test being carried out at a temperature of 23 + 1°C.
4. Spherical Symmetry
The ball must not be designed, manufactured or intentionally modified to have properties which differ from those of a spherically symmetrical ball.
5. Initial Velocity
The initial velocity of the ball must not exceed the limit specified (test on file) when measured on apparatus approved by the USGA.
6. Overall Distance Standard
The combined carry and roll of the ball, when tested on apparatus approved by the United States Golf Association, must not exceed the distance specified under the conditions set forth in the Overall Distance Standard for golf balls on file with the USGA.
United States Golf Association – www.usga.org/default.aspx
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