The leaders are about to tee off for their final round at TPC Summerlin. Co-leaders Nick Watney and Kevin Na have a 2 p.m. ET (11 a.m. local time) tee time with Robert Garrigus, who enters the day one shot off the pace. Heading into today’s finale, there have been 1,592 birdies and eagles at TPC Summerlin. Those stroke-saving opportunities at TPC Summerlin can lead to a lot of volatility on the leaderboard, especially if a player gets hot, but doesn’t necessarily allow for someone to come from out of nowhere and win. Those rallies typically require the leader or leaders to stall, and even give shots back on Sunday afternoon. Just one player in the current top 17 (David Duval) has posted a round in the 70s this week, and that was an even-par 71 in Round 2. There have been 16 rounds of 64 or better this week, but a year ago there were just three rounds of 64 or better on Sunday in Vegas. No one inside the top 20 shot in the 70s in that finale. Jonathan Byrd defeated Cameron Percy and Martin Laird in a playoff. Laird opened the final round atop the leaderboard with Byrd one back and Percy two off the pace. This is the wild and unpredictable 2011 season, though. Even if this week doesn’t feature a major comeback, there are still 13 players who start the afternoon within four shots of Watney and Na.