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Coming back to those between-round changes to the course that will take place I mentioned earlier... They are as follows:

• The 1st and 18th holes alternate between par four and par five, retaining par for the course at 70. As a result, the first could either be 598 or 496 yards long, with the 18th switching between 605 and 524 yards in length.

• The par-three 9th will be radically different from one round to the next, played either downhill, from a longer elevated tee, or uphill.

• The 15th will either be twice as short or twice as long from one round to the next courtesy of tee boxes that are 120 yards apart. At its longest it is 246 yards and at its shortest it is 123 yards.

One thing is for certain, when Matt Kuchar hits a good shot we're going to know about it. His tee shot on the par-three third lands and rolls to within a few feet of the hole. "Kuuuuuuuch!" is the crowd's now stock response.

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Things all went a bit hyper for Rory McIlroy at the Masters earlier this year, as the media turned its bright glare on the world number one as he attempted to complete a career grand slam. He failed, as you know. And has since admitted the focus on him was a tad distracting.

However, he says he feels much calmer ahead of the US Open, perhaps helped by the the media changing aim to the new hot, young thing on the golf scene: Masters winner Jordan Spieth.

"It has been nice not to have all the attention on me. I felt that is what it was at Augusta and I couldn't get away from it," McIlroy told BBC Sport. "I will be disappointed if I do not win a major this year. My seasons now are based on major wins. I have won three times this year which is great, and lead the world rankings."

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Agonising. Mickelson judges the line right but the length an inch wrong as his putt at the 13th curls towards the hole and holds in front of the hole. A second bogey of the round drops him to two-under.

Mickelson's second shot at the 13th has found one of Chambers Bay's taxing bunkers, on the edge of the green. He does well to get it out the dust and on to the green but he still has plenty to do to salvage a par.

A quick shot at the leaderboard shows that Lefty has been joined on three-under by fellow American Dustin Johnson.

If Rory McIlroy is going to challenge here, the kind of putt he is stood over at 18 is the kind he needs to sink. It is about seven or eight feet away and for birdie. And he puts it an inch to the left. So the Northern Irishman stays level, four off the leader.

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Right, so here are some basic facts about Chambers Bay...

The par-70 public course is just south of Seattle, overlooking Puget Sound near Tacoma, and is the newest course in 45 years to host the US Open (it opened in June 2007).

The course could be as long as 7,900 yards or as short as 7,200 depending on the way they choose to set up the holes, four of which can be drastically altered (more of that in a minute).

There is only one tree on the entire course, a Douglas Fir behind the 15th green, but players will have to contest with the 10ft-deep "Chambers Basement" bunker (the deepest in US Open history) and trains running alongside the 17th hole.

Wait. Hold on. Patrick Reed is now the leader, rattling in a superb long putt across one of these mottled Chambers Bay greens - the 18th to be exact (he started on the 10th) - to move to four-under. Mickelson can't match his birdie with a shorter effort at 11 and stays at three-under.

Chambers Bay is already in the process of chewing some players up ahead of spitting them out. Not Phil Mickelson, though. Lefty has made a cracking start in pursuit of the one major title that has so far eluded him (although he has been mighty close) and is currently the joint leader on three-under with fellow-American Patrick Reed. They are a shot ahead of a group that includes Matt Kuchar and Dustin Johnson. Rory is even par at the moment.

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"You feel like you've played 18 after you've played nine."

"I think it's a course that involves a hell of a lot of luck."

"A complete farce."

This is just a small collection of what has already been said about Chambers Bay, the links course in Seattle that will play host to the 115th US Open, that got under way earlier today. It is the issue that has dominated the build-up and will no doubt continue to do so if some big players post big scores in the first two rounds.

But regardless of wind, sand and trains, good golf will always prevail. And we are going to see plenty of it in the next four days.