Pristine golf course
One player determined to make up for a little lost time is McIlroy who, surprisingly, last topped the rankings in 2015.
The Northern Irishman, who is presently ranked No.5, would like to reach the pinnacle once again and is looking to set the process rolling with victory at a pristine, beautifully prepared Sheshan International. "It's a great accolade and a great honour to be world No.1 and I'd love to get back there one day," McIlroy said on the eve of the tournament.
One of the best
McIlroy, who has had three weeks off since playing in the winning Europe Ryder Cup team, certainly fancies his chances on a course he describes as "one of the best" in this part of the world.
His last win came at the Arnold Palmer Invitational in the US in March so he is keen to finish the year on a high note.
Looking to consolidate
While McIlroy is looking to get back to winning ways, Koepka is looking to consolidate his position at the top of the rankings.
"I'm looking forward to teeing it up as No.1," Koepka said.
"That's something every golfer dreams of and wants to accomplish. I'm looking to build on that lead and grow it, so that I can be No.1 for a while. The goal isn't just to get there, it's to stay there."
Defending champion
Rose, the defending champion, would concur. Victory at Sheshan International kick-started a superb season for the Englishman, who went on to win three more times worldwide before sealing the FedEx Cup on the PGA Tour.
Along the way, he became only the fourth Englishman, behind Nick Faldo, Lee Westwood and Luke Donald, to become world No.1. "That was a milestone moment," Rose said. "If I had to choose one highlight from the year that would be it. Getting to No.1 is a career's amount of work.