Has Jason Day produced the greatest year by an Australian golfer ever?

"How long until he becomes No.1 in the world?"

Of all the questions during Jason Day's commanding six-shot win at The Barclays, that is the one that occupies the Australian's mind more than any other, for we know how badly he wants it.

He could yet do so by the end of this year, but according to the legendary Nick Faldo, the world No.3 has unofficially gone past the game's marquee man, Jordan Spieth, who this week lost his No.1 mantle back to Rory McIlroy as the game's "Big Three" continue their takeover.

"This guy is the best player in the world right now," the six-time Major Champion said about Day during commentary of The Barclays, having posed the above question early in the round.

"Jordan was before, but right now and over the last month, this is the guy they've got to beat."

And there are a couple of other questions worth asking right now, too.

For instance, has any Australian golfer had a better year than Jason Day's in 2015?

The 27-year-old is on the verge of climbing a mountain no other golfer from this country has been able to. That is, winning the PGA Tour's coveted US$10 million FedExCup - which is basically the end-of-season "premiership" for golfer's on the world's top circuit introduced in 2007.

In AFL terms, Day's win at the Barclays on Monday morning, AEST, was kind of like winning a qualifying final in the first week of September.

He will now head into the remaining two events of the Tour Playoffs - the Deutsche Bank and BMW Championships - ranked No.1 in the standings and in the box seat to stay there for the grand final the following week, which is the Coca-Cola Tour Championship.

If he were to win one, two or all three of those tournaments and lift the FedExCup, Day would set a new standard of excellence for Australian golf.

Our best of the modern era, Greg Norman, had a flagship year in 1986 when he won two PGA Tour events, one on the European Tour and of course his first major - the 1986 Open Championship - to go with second-place finishes at the Masters and PGA Championship that year.

He also won a bunch of minor events in Australia that don't really come into the equation, because the Australian summer is much different now and Day has elected not to play our domestic events this year due to the birth of his second child.

This was the year of the "Norman Slam", as he became the first player to hold the 54-hole lead in all four Major events, thus playing in the final group and having the greatest chance ever of achieving the Grand Slam that Spieth flirted with this year.

Day, in comparison, has now won four times this year - starting with his win at the Farmers Insurance Open in February - and three times in his past four starts - the Canadian Open, his breakthrough major title at the PGA Championship and now the Barclays.

It is the first time since Bruce Crampton in 1973 that an Australian has won four events on the US PGA Tour in one season.

So good has Day been that his play has forced the game's leading judges to ponder another question they never thought they would bother asking: Has anyone had a better year than Jordan Spieth?

It seems implausible that a man who won both the Masters and the US Open could not win the PGA Tour's Player of the Year award.

However there is a real danger that Day could yet steal the award, becoming the first Australian to do so since Norman turned that trick in 1995 - in a magnificent year in which "The Shark" never won a major but became No.1 in the world.

Day is in a zone right now, one that Norman once had access to back in his heyday, if not similar to that which Tiger Woods use to frequent more than any other of recent times.

The Queenslander's win at The Barclays was an encore to his history-making score-to-par in a major at the PGA Championship.

He went 63 and 62 over the weekend to blitz the field - making only one bogey along the way.

He is starting to create superstar moments, too, much like Spieth has done all year.

"Oh my goodness, this guy is sensational": that was the call on commentary when Day rolled in a long, winding putt on the 15th hole that was so tough that the TV broadcaster's predictor gave him just a six-percent chance of making it.

He pumped his fist and let out a big roar to match that of the crowd's.

Since the US Open in late June, he has produced 20 straight rounds under par.

The toughness factor has played big for Day.

Not only did he guts it out to finish tied 9th at the US Open, overcoming a bout of vertigo that caused him to collapse, he came through at The Barclays despite having to withdraw from the pro-am with a back complaint.

Golf is such that one's consistency of contending is not recognised until you stop contending and start winning.

That is true for Day, who has had five top 10s to add to his four wins this year - including a tied fourth at the Open Championship and the US Open finish.

Spieth, though, has been on another level in terms of consistency - completing 10 top 10 finishes to go with two other wins on the PGA Tour in 2015.

He also finished second (PGA Championship) and tied fourth (Open Championship) in the other two majors he didn't win, all of which means Day needs to keep winning over the next three weeks to make those judging the Player of the Year award forget about the incredible body of work Spieth has put together.

Then, again, you wouldn't put anything past Day right now.