What Are the Odds of a Hole-In-One?

Justin Thomas Masters Justin Thomas Masters
Justin Thomas plays his shot from the 14th tee during the second round of the Masters on April 12, 2019 in Augusta. He later shot a hole-in-one on the 16th hole during the final round on Sunday. Kevin C. Cox/Getty Images

A standard, regulation-sized golf ball is a smidge smaller than 1.7 inches (4.3 centimeters) in diameter. Or, for comparison's sake, just a little larger than your garden-variety ping pong ball.

The standard, round cup that snuggles into an earthen hole on your run-of-the-mill manicured green on any of the more than 15,000 golf courses in the United States — or the more than 33,000 throughout the world — is, by rule, 4.25 inches (10.8 centimeters) in diameter.

Small ball. Big hole. So, what's the problem? Said no one who ever swung a club at a golf ball in his or her life.

Golf is hard. Getting that little ball into that not-so-big cup is way more difficult than Tiger Woods and those other professionals make it look. And for proof (other than trying it yourself, that is), the non-golfer should consider the Holy Grail of golf, the ever-elusive, never-foreseen, always-magical hole-in-one.

If golf is hard — and, again, give it a try if you've never — the quest for a hole-in-one is downright cruel. The odds of it are not hitting-the-lottery odds. But they might as well be.

To be sure, pros like Bryson DeChambeau and Justin Thomas can pop in an ace every once in a while. (And on the same day at the most prestigious tournament in the world, The Masters, no less.) But for your average golfer? 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. Which sounds like a lot. Except golfers play somewhere around 450 million rounds of golf every year.

That means a hole-in-one is officially registered about once every 3,500 rounds. (A round is generally considered 18 holes, though the United States Golf Association sometimes accepts a hole-in-one on a shortened round.) If you play a round of golf a day, it'd take more than 9.5 years to get in 3,500 rounds. If you play twice a week, it'd take you more than 33.6 years to get in 3,500 rounds.

Another business, National Hole-In-One Insurance — it provides protection to golf courses that give out prizes for holes-in-ones during competitions — estimates that, for your average player, the odds of holing out in one stroke are 12,000 to 1. A PGA Tour pro, like DeChambeau or Thomas, faces 2,500-to-1 odds. On every chance at an ace.

The numbers, undoubtedly, are a little sketchy. The USGA isn't exactly looking over every golfer's shoulder. Video proof is not required. A credible witness is about all you need.

Still, as any weekend duffer who's gone at the pin on a par 3 knows, just about any ace (flat-out cheating and do-overs notwithstanding) is a legit ace.