You might have heard, again as a useless trivia that golf balls have 320 dimples. Although there are golf balls with this number, this is not a necessity. The Rules of Golf, governed by the USGA, state in Appendix III that the diameter of a “conforming” golf ball cannot be any smaller than 1.680 inches (42.67 mm), and the weight of the ball may not exceed 1.620 ounces (45.93 g), but there is no mention in the dimples.
As a matter of fact, the only mention is that it has to be spherically symmetrical, so dimples vary. They generally range from 250 to 450, though there have been balls with as many as 1070 dimples (414 large and 656 pinhead sized ones)!
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