How many golfers have shot a 63 for a round in a major? How many of those won the tournament?
Rory McIlroy is the 22nd golfer to achieve the feat after carding a 63 in the opening round of this year's British Open.
Two golfers — Greg Norman and Vijay Singh — have done it twice.
Johnny Miller famously was the first to achieve it in the 1973 U.S. Open. Miller's 63 came in the final round at Oakmont. He made up a six-stroke final-round deficit to win the tournament.
Other members of the "63 in a major" club have not had as much luck.
Only four of the other 22 record rounds have come when the golfer won the tournament: Jack Nicklaus won the 1980 U.S. Open after firing a 63 in the first round; Ray Floyd (1982 PGA Championship, first); Greg Norman (1986 British Open, second); Tiger Woods (2007 PGA Championship, second).
McIroy's round was the eighth to come in the British Open. The others are: Mark Hayes (1977, second round); Isao Aoki (1980, third); Norman; Paul Broadhurst (1990, third); Jodie Mudd (1991, fourth); Nick Faldo (1993, second); Payne Stewart (1993, fourth).
McIlroy set a dubious record Friday during his second round, as he became the first golfer to not break 80 the round immediately following his 63. His 80 was five shots worse than the previous record holder in Bruce Crampton, who shot a 75 in the second round of the 1975 PGA after carding a 63 in Round 1.
Unless he comes back with a great third round, McIlroy will probably avoid the ignominy suffered by Norman in the 1996 Masters.
He followed his first-round 63 with a 69 to build a huge lead over the field. Of course, he eventually surrendered a six-stroke lead at the start of the final round to Nick Faldo. Norman finished five strokes back, completing the 11-stroke Sunday turnaround.