Jason Day is currently the best player on the planet.

Is he the best player of the 2014-15 season?

Following his latest masterpiece, a six-shot romp he capped Sunday at Conway Farms Golf Club to win the BMW Championship, Day improved his case for the PGA Tour player of the year award that was once considered to be a lock for Jordan Spieth. Spieth won the year’s first two majors, made a gallant run at history in coming up one shot short in the British Open and has two other wins.

Next week’s Tour Championship by Coca-Cola, the finale of the FedExCup Playoffs, could decide matters among the players, who vote on the award.

“I still think it’s him,” said Day, who has won four of his last six starts, of Spieth. “I’m hoping to win next week and get people talking about it more. It might change some people’s minds a bit if I go out and win next week.”

Day has two wins in the playoffs and is No. 1 in the standings heading to Atlanta for The Tour Championship at East Lake Golf Club. He’ll head there as the No. 1 player in the world rankings, too, having fulfilled a childhood dream Sunday when he shot 2-under-par 69 to finish at 22 under and six clear of Daniel Berger and seven clear of Scott Piercy.

Former No. 1 Rory McIlroy, Rickie Fowler and J.B. Holmes finished eight back.

“It’s kind of been a dream run for me,” said Day, 27, who shot 61-63-69-69. “All I want to do is win. Ever since the (British) Open, my mind changed and my attitude has been to win.”

Day’s won four events since tying for fourth in the British Open, including the PGA Championship, his first major. He has five wins this season and seven in his career. With his victory in the BMW Championship, he joined Vijay Singh and Tiger Woods as the only players in the last 20 years to win five or more events in a season (Woods did it 10 times).

And they have been authoritative wins for Day. He was 17 under when he won the RBC Canadian Open the week after the Open. He was a major-championship record 20 under in winning the PGA Championship, and he was 19 under in winning The Barclays, the first event of the playoffs. He is 101 under in his last seven events.

Day is one of five players who will automatically win the FedExCup — and the $10 million bonus — if he wins in Atlanta. Spieth, Fowler, Henrik Stenson and Bubba Watson are the others in a very nice spot.

While Day’s confidence level is sky high, Spieth’s is a bit shaky but trending upward after he missed his last two cuts. He finished 11 under and in a tie for 13th. A win in Atlanta would wrap up player of the year honors, his two majors making the difference. Some players think that’s enough to give him the award no matter what Day does. Others aren’t so sure.

As for Spieth, he doesn’t want to think about that right now. Instead he’s thinking about his game.

“As poorly as I felt with my game, to shoot double digits under par, so it’s actually a big step forward because I felt a little bit better than I did after those last couple events,” he said. “But I still am lacking a bit of confidence in my game to really get through a lot of shots, which means I’m lacking a bit of consistency. ... I’m making way too many over-par holes, too many mistakes that I’m not able to recover from.

“You know, that’s good, though. It’s good because I’m at 11 under, almost a top 10, and I feel like I really didn’t have my game this week. I need to work hard.”