The odds of an amateur golfer shooting a hole-in-one are roughly 12,000 to 1. The players who qualify for The Open Championship, however, are not amateurs, with a few exceptions – and the exceptions are only amateur in their professional status, not in their golf skill.
The last 40 years tell us it's more likely that not that there will be at least one hole-in-one at The Open Championship on an annual basis.
Here is a brief history of holes-in-one at The Open.
The first recorded hole-in-one at The Open was hit by Tommy Morris Jr. in 1869. He holed out his tee shot on the 8th hole in the first round and that year he went on to win his second of four career championships at The Open.
Morris Jr., who became the youngest competitor in the history of The Open when he entered at 14 years old in 1865, holds the top three marks for the youngest winners of The Open, winning at 17, 18 and 19 years old.
No one who has hit a hole-in-one at The Open has won the major since 1961.
Grillo stepped to the 200-yard, 13th hole at Royal Portrush Golf Club and the announcers mentioned that he may have a been given a break on the hole placement. Sure enough, Grillo hits it to the front of the green where it rolls and rolls, finding the bottom of the cup on one stroke. Grillo finished his first round at the 2019 Open Championship 2-over.
Louis Oosthuizen hit a hole-in-one from 178 yards out on the 14th hole at Royal Troon during the first round of The Open in 2016. Despite shooting an opening-round 71, he missed the cut. Remarkably, Oosthuizen also recorded as hole-in-one at the Masters in 2016.
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The late Gene Sarazen, a seven-time major champion who completed the career Grand Slam, is the oldest player to record an ace at a major. In 1973, when he was 71 years old, he holed out from the tee box with a 5-iron on the 8th hole at Royal Troon.
The 147th Open Championship media guide includes detailed historical hole-in-one data since 1981.
There have been 26 holes-in-one in the last 38 years of The Open with as many as three in one year. There was at least one hole-in-one in 20 of those 38 years. We can add No. 27 with Grillo's ace in 2019.
Royal St. George's and Royal Troon are tied for the most holes-in-one by venue since 1981. Each course has been witness to five aces, with Dustin Johnson also acing the 16th hole at Royal St George's in 2011 and Tom Watson hitting a hole-in-one on the 6th hole. Eight different courses have been home to a hole-in-one since '81.
Royal St George's and Royal Troon also hold the high-water mark for aces in a year since the 1980s.
The 16th hole at Royal St George's was aced three times in 1981, including twice in the fourth round, while three different players – Pierre Fulke, Daniel Olsson and Dennis Edlund, all from Sweden – hit a hole-in-one on three different holes at Royal Troon in 1997.
Since 1981, Carnoustie is the only venue that has hosted The Open and not had at least one hole-in-one. Carnoustie hosted The Open in 1999 and 2007. Paul Lawrie won The Open in 1999 with a score of 6-over, so a hole-of-one would have made a major difference for any golfer in contention for the championship.
The longest hole-in-one at The Open since 1981 was more than 70 percent longer than the shortest hole-in-one. Frank Lickliter II recorded an ace from 212 yards out on the 5th hole at Royal Lytham & St Annes in 2001, while Ernie Els' first-round hole-in-one at Royal Troon in 2004 was just 123 yards.
Since 1981, the 2nd, 3rd, 10th, 17th and 18th holes at host courses for The Open haven't had a hole-in-one.
Fourteen of the 26 holes-in-one since 1981 have come the middle of the back nine, between the 11th and 16th holes. Twelve holes-in-one happened between the 4th and 9th holes.
The Irishman is the only golfer since 1981 to record two aces at The Open. He did so in 1992 at Muirfield, then four years later at Royal Lytham & St Annes. His best career finish at The Open was tied for 14th in 1996.