The tweaking of the points system several years ago allows for a greater emphasis on performances through the Playoffs rather than a situation which allows the winner of the FedEx Cup being decided before the Tour Championship and thus Mahan has been able to make a big move forward.
Despite a bogey at his final hole Mahan had done enough with three consecutive birdies at the 15th, 16th and 17th to edge ahead of a Stuart Appleby, Cameron Tringale and Jason Day.
Mahan won his sixth PGA Tour title and his first in more than two years with his win and must now come into consideration for a berth in the Ryder Cup side, an event he has played on two previous occasions along with four Presidents Cup appearances.
Mahan was not totally convinced about his Ryder Cup chances but surely this must be a timely reminder to Tom Watson.
"I don't know," Said Mahan after Saturday's third round. "Obviously this would help my chances quite a bit. I really have no clue what he's thinking. There's been very little kind of, I don't want to say communication, but they have held their cards pretty close. So I don't know if anyone has any really clue what maybe they are looking for.
"But I know a win would definitely improve my chances. So you know, right now, it's just with the FedExCup Playoffs and everything, a win means a lot from a points perspective and everything else. Got to be aggressive and go out and try to win.
Appleby, Tringale and Day all led at various stages, Appleby birdying five of the opening six hole sof the back nine to take the lead and appear on track for his 10th PGA Tour title and his first for four years.
Appleby was unable to maintain the momentum over the closing three holes but after starting the week in 98th position and on the cusp of making it to this coming week's Deutsche Bank Championship in Boston, he has now jumped to 19th and appears likely to play all four of the Playoff events.
For Day it was his second runner-up finish of the season to go with his victories at the World Cup and the Accenture Match Play Championship.
Tringale has yet to win on the PGA Tour and while a bogey at the last might have cost him outright second he will be delighted with what is his biggest cheque in the game.
Australians who have qualified to play next week's Deutsche Bank Championship are Adam Scott, Jason Day, Stuart Appleby, John Senden, Marc Leishman, Steve Bowditch, Matt Jones and Geoff Ogilvy who just snuck through on the number.
100 players will tee it up in Boston, that number reduced to 70 following the completion of play on Sunday at the Deutsche Bank Championship. Those 70 players will advance to the BMW in Cherry Hills in Colorado.