Kevin C. Cox/Getty ImagesA standard, regulation-sized golf ball is a smidge smaller than 1.7 inches (4.3 centimeters) in diameter. The odds of it are not hitting-the-lottery odds. Let's go to the scorecard:According to the National Hole-In-One Registry, which a tad immodestly back-slaps itself as \"The Premiere Worldwide Hole-In-One Golf Registry,\" somewhere north of 128,000 holes-in-one are registered every year. (A round is generally considered 18 holes, though the United States Golf Association sometimes accepts a hole-in-one on a shortened round.) NOW THAT'S INTERESTING The National Hole-In-One Registry says that the average length of a hole on which an ace is scored is 147 yards.