In the end the outcome was exactly as expected on Sunday even if the manner was in complete contrast to three previous days of flawless golf from Brooks Koepka.

All manner of records were expected to tumble en route to defending the US PGA Championship after a seven-shot lead had been opened over a pack that wasn't so much chasing as desperately clinging on for dear life.

But in golf, as in life, there are no guarantees and Koepka had to ride out a storm after a back nine that saw him drop five shots in the space of seven holes and provide more than a glimmer of opportunity to good friend and gym buddy Dustin Johnson.

Ride it out he did, though, and the newly crowned world number one proved that his pre-tournament confidence was not misguided.

The idea of confidence can be divisive. The line between confidence and arrogance can often be a thin one, a notion that is exacerbated tenfold when it comes to professional sports.

Many have been 'guilty' of stepping the wrong side of the divide in the pursuit of greatness.

Perhaps Koepka's perceived tendency to do so is why there has been a lack of acclaim along a path that has been careering towards greatness. 

Indeed, before a ball had even been struck at Bethpage Black this weekend, Koepka was in full mind-game mode when discussing a phenomenal record in the majors over the past two years.

"I don't see why you can't get to double digits," he told a press pack, whose ears would have immediately pricked up. 

"I think you keep doing what you're supposed to do, you play good, you peak at the right times… I think sometimes the majors are the easiest ones to win.

"Half the people shoot themselves out of it, and mentally I know I can beat most of them, and then from there it's those guys left, who's going to play good and who can win.

"I don't see any reason it can't get to double digits."

It was the boldest of assertions that may have rubbed some the wrong way. But does he care? Not a jot. Should he? Absolutely not.

In a mostly individual sport like golf, having that cocksure, brash attitude is a trait that can provide a psychological advantage before even taking to the tee.

Ask yourself, would Tiger Woods have been the same player without that single-minded swagger that made him the world's most dominant and most sought-after sports star for over a decade?

Moreover, why shouldn't Koepka believe he can get to double digits? Yes, history is not exactly on his side. Only Jack Nicklaus, Tiger Woods and Walter Hagen have achieved it. Ben Hogan, Gary Player and Tom Watson are among the greats that came close without lighting the cigar.

But right now there is not even an argument to be had. Koepka is simply the dominant force in men's major golf. Four of the past nine have been won by the American, one he didn't even play due to injury, two others have resulted in top-10 finishes.  

Since the 2014 Masters, eight different Americans have won a major title, while Rory McIlroy – the man most would have deemed the likeliest to reach double digits – has lifted two of his four.

At that time it would have been unthinkable to suggest Koepka as more likely than Jordan Spieth, Dustin Johnson or McIlroy in a hypothetical race to 10.

Now we're in a scenario where to consider anyone but Koepka capable of reaching a fabled feat looks naive, bordering on foolish.

Suggestions of Woods-esque era of dominance are probably premature, indeed Adam Scott summed up the feeling pretty succinctly after round three on Saturday.

"It's not quite the same, and that's no disrespect to Brooks," the Australian said. 

"I think comparing anything to Tiger is a little unfair in a good or a bad way. It would be probably bringing down what he managed to accomplish. He did this multiple times in majors, let alone regular tournaments."

His last-nine wobble at Bethpage certainly betrayed his usually unflappable nature.

And regardless of that dip, it still takes a huge leap of faith to believe Koepka can enjoy the same sort of hold Woods had over the world of golf.

But Koepka is the kind of character that has little time for comparisons anyway. To hell with history. He will simply want to continue blazing a trail in his own inimitable style.

His is a path not familiarly trodden. In 2012, Koepka played at the same PGA Tour Qualifying School event as Spieth.

Neither made the grade, but while Spieth earned a PGA Tour card just three months later thanks to a more traditional route after receiving sponsor exemptions on the Web.com Tour, Koepka would take another three years to receive his.

The intervening period was a hard-knocks apprenticeship on the European Challenge Tour and European Tour, including stops in Kenya and Kazakhstan – not exactly noted as golfing hotbeds.

It is an education that has instilled an iron will to win at all costs and cope with the incomparable pressure cooker of major golf. Lessons that will have been handy as the bogeys racked up and Johnson moved within one stroke on Sunday. Ultimately, he got the job done.

So, whatever side of the confident-arrogant line you think he falls on, it doesn't matter. Koepka is a major-winning machine that will take some stopping.