There's another on-course battle going on at East Lake Golf Club this weekend between Jordan Spieth and Jason Day that involves one of the oldest and most prestigious awards in golf.
Since 1937, the PGA of America has awarded the Vardon Trophy -- named after legendary British professional Harry Vardon -- to the touring professional with the lowest adjusted scoring average.
VARDON TROPHY: Rory McIlroy wins award in 2014
Heading into the Tour Championship, Spieth had averaged 68.984 strokes per round in 87 total rounds. That's slightly better than Day's 69.163 average over 71 rounds. That's incredibly close -- a difference of .18 strokes over the entire season -- with just four rounds to be tabulated. And in either case, it'll be the first Vardon Trophy for the winner.
The final results will be released on Monday.
The award is based on a minimum of 60 rounds, with no incomplete rounds, in events co-sponsored or designated by the PGA Tour. The adjusted score is computed from the average score of the field at each event.
Rory McIlroy won the Vardon Trophy last season by averaging 68.82 strokes through 66 complete rounds. He edged Sergio Garcia (68.95), who completed 61 rounds. It was his second Vardon Trophy in three seasons. In 2013, Tiger Woods picked up his record ninth Vardon Trophy.
Fourteen players have won multiple Vardon trophies, but surprisingly, Jack Nicklaus is not among that group. Billy Casper and Lee Trevino have five each, while Arnold Palmer and Sam Snead won the Vardon Trophy four times.
The first winner was Harry Cooper in 1937, when the award was based on a point system. It was not awarded during World War II, then switched to adjusted scoring average when it resumed in 1947.