As the final four prepare to battle for the WGC-Accenture Match Play Championship on Sunday, here are some things you should know before the last four matches of the week at Dove Mountain.
• Rory McIlroy and Lee Westwood face off in the semifinal. The winner will compete in the final for a shot at the No. 1 ranking. The loser will fall to No. 3 in the Official World Golf Ranking.
• Westwood may not win, but he is a tough out with the No. 1 spot on the line. Westwood won in Asia last April to retake the top spot from Martin Kaymer as a birthday present to himself. Threatened by Luke Donald last May to lose the ranking he had just regained, Westwood took Donald to a playoff in the BMW PGA Championship. Donald won and hasn't relinquished the No. 1 spot since.
• A win by either McIlroy or Westwood in the final would mark the second consecutive year the top OWGR spot has changed hands at Dove Mountain. By reaching the final last year, Martin Kaymer became No. 1 in the world.
• Hunter Mahan will be vying for his second World Golf Championships win. He took the WGC-Bridgestone Invitational in 2010.
• No player has taken all four of the current WGCs. Tiger Woods leads with three of four.