As the giant flag of “Old Glory” flew at half-mast close by the 18th green, a poignant reminder of the tragic shootings in Florida, those 156 players here competing in this 116th edition of the US Open championship went about their business. Some putted. Some chipped. Some embarked on final practice rounds, all with the intent of claiming a revered trophy on a famed course. Only one of them can actually savour glory.

Who? Now, that is the question. For all of the plotting and planning that most players have indulged in for the past few days in preparation at Oakmont Country Club, Angel Cabrera – who completed the task in 2007 – left us thinking that perhaps players put too much thought and worry into it all. “It’s difficult to say that there is any strategy at all,” said the Argentine.

The reality is all facets of the game come into play on a course that features thick rough, penal bunkers, narrow fairways and exceptionally fast greens. If you thought too much about it all, you’d be driven demented. And, then, there is the weather factor: a front bringing thunderstorms is expected to pass its way through western Pennsylvania today which will likely disrupt play but also soften the greens.

“It’s the most difficult golf course I have ever seen but that doesn’t mean it is unplayable,” said Shane Lowry, one of three Irishmen in the field along with Rory McIlroy and Graeme McDowell.

Someone will always find a way. When Cabrera won here in 2007, his 72-holes winning total – five-over-par – was sufficient to get the job done.

“I think that there’s no reprieve off the tee, there’s no reprieve into the greens, and there’s certainly no reprieve on the greens,” said Phil Mickelson, adding: “Now, with all that being said, I believe it also gives me the best chance (to win a US Open) because after 25 years, you have to really know how to play this style of golf . . . . I would love to see it cross the line the way US Opens often do, and become a little bit over the edge. That actually benefits me because we’re going to have a winner at the end of the week. Whatever that score is, who cares if it’s 5 under or 12 over, doesn’t matter, the lowest score wins.”

There are many subplots, too. Mickelson, for one, will get another chance to complete the final leg of a career Grand Slam. The US Open is the only Major championship to have evaded his clutches (he has six runner-up finishes) and, having finished second behind Daniel Berger on Sunday in the St Jude Classic, Mickelson interrupted his preparations here to fly back to California to attend his daughter’s school graduation.

Bounce back

Then, there’s Danny Willett’s attempt to back up his Masters win with another Major title; Jordan Spieth’s bid to bounce back from his Masters meltdown and to retain his US Open crown; Jason Day’s mission to affirm his world number one ranking with another Major title; Rory McIlroy’s quest to claim a fifth career Major and first since the US PGA in 2014.

Then, there’s Rickie Fowler, Dustin Johnson, Henrik Stenson, Branden Grace, Sergio Garcia, Hideki Matsuyama and more who are all seeking a first Major.

For McIlroy there is the awareness that his recent form – winning the Irish Open at The K Club and tied fourth at The Memorial – in his last two starts has him primed to contend. Even the arrival of the dark clouds to douse rainwater on parched terrain would seem to have answered his prayers, the Northern Irishman’s track record on softened courses unparalleled in recent years where his booming drives invariably find receptive fairways.

What will it take to win? Perhaps it will have as much to do with what goes on in the six-inches from ear to ear as anything else. As South African Grace put it, “I think the guy with the best head is going to win at the end of the week, the guy who can stay patient.”

In play

Easier said than done of course; and especially so on such a set-up. “We always say each and every week, ‘it’s a bomber’s course’. For the most part, it’s a bomber’s game, our generation. It’s not like that this week,” said Day.

In other words, it’s about more than hitting booming drives. It’s about keeping the ball in play, and knowing where to bounce approach shots, and avoiding fairway bunkers, and getting the pace on devilishly quick greens. The sum of all the parts will produce a champion.

“It is one of those weeks there will be a lot of broken men leaving here on Sunday evening and on Friday evening [after the cut] as well. You just have to get on with it, the only week that’s going to be this tough this year. It is almost an enjoyable challenge,” observed Lowry.

A total of 156 players, 12 past champions, 11 amateurs. McIlroy, though, expects the cream to rise to the top. One of the usual suspects.

McIlroy is one of them.