Who’s No. 1? Four players could hold the world’s top spot after the Tour Championship

After his runner-up finish at last week’s BMW Championship, Justin Rose holds the World No. 1 ranking — for now. Several challengers have the chance to overtake him at this week’s Tour Championship at East Lake.

To guarantee that he’ll hold onto the top spot in the world, Rose will need to win this week’s event. But each of the world’s top four have the chance to usurp the throne. Here’s how:

Brooks Koepka, who moved to No. 2 this week despite not playing, could finish anywhere in the top 18 and take over from Rose should the Englishman have a poor week.

Brooks Koepka

World No. 2 Brooks Koepka has a chance to grab the top spot with a high finish this week.

No. 3 Dustin Johnson could reclaim his top ranking with a top-eight finish and some help from Koepka and Rose.

And fourth-ranked Justin Thomas could get back to No. 1 with a win or solo second. Further scenarios are outlined here.

The ranking is unusually tight at the top. Rose is No. 1 at 10.245 points; Koepka sits at 10.204, Johnson at 10.135 and Thomas at 9.573. Rory McIlroy is fifth at 7.285.

Tiger Woods projects to move as high as 13th with a win this week.