Jordan Spieth and Jason Day were idle this weekend, but their positions in the Official World Golf Ranking moved.
Day regained the No. 1 spot in the ranking, a function of the rolling 104-week formula. Spieth had been No. 1 for three weeks, which he earned with his win at the Tour Championship, which clinched the FedEx Cup in September.
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Rory McIlroy, who finished T-26 at the Frys.com Open on Sunday, remains third.
Let's briefly explain how these changes happen when the principles involved aren't playing:
The OWGR formula is computed over a rolling 104-week (or two-year) basis. Players earn points when they compete based on two factors: the strength of field, as determined primarily by the number of top 200 players in an event, and where they finish in a tournament. When players earn points, they maintain their full value for 13 weeks, or one-quarter of a year. In the 14th week after points are earned, they start to lose value in equal increments for the next 91 weeks, before they become worthless. A player's ranking is based on how many points they have banked currently over the number of tournaments they've played in the current 104-week period.
Since players and tours don't keep the same schedule year after year, there are times when players lose significantly more points than they might otherwise. That brings us here, with Day taking No. 1 again.
Since Spieth became No. 1 after a runner-up PGA Championship finish, the No. 1 spot has changed hands frequently. After a two-week initial reign, Spieth lost the top spot back to McIlroy after The Barclays, in which McIlroy didn't play. Spieth then got it back a week later. McIlroy got it back for the off week of the PGA Tour playoffs. Day took No. 1 after winning the BMW Championship, his second win of the FedEx Cup playoffs. Then Spieth's East Lake win got him back to No. 1.
With most top players slowing down toward the year's end, expect this kind of jockeying to continue. Day won't play again until the Hero World Challenge in December. Spieth will play that event and, before it, the WGC-HSBC Champions. McIlroy could pass them both by virtue of his finishes in the European Tour's four-event Race to Dubai Finals Series.