Three bookmakers have priced this market identically in the latest edition of follow the leader (or else the prices come from precisely the same place), and they're wrong.

Adam Hadwin is a worthy favourite, that is beyond dispute. He is a more decorated golfer than Mackenzie Hughes and his form over an extended period has a much more solid look to it.

Hughes, however, is light years ahead of Garrett Rank, a 31-year-old NHL referee who is talented, no doubt, but will be playing in his first US Open and, as an amateur, has no designs on making a living from this sport.

Yet bet365, Sport Pesa and 10Bet all bet 4/1 Hughes, 9/2 Rank - in other words, they rate their respective chances of outscoring Hadwin as roughly equal.

Sky Bet have left Rank out of their market and offer 1/2 Hadwin and 6/4 Hughes. I suspect they're slightly off and that William Hill's 4/9 Hadwin and 2/1 Hughes is more accurate, while they can afford to throw Rank in there at 9/1 having correctly acknowledged that his prospects are limited.

The bet has to be Hughes, even if his form doesn't appear pretty.

In among a run of zero top-40 finishes this year have been recent hints that he's turned the corner, notably a 66 at the St Jude, rounds of 67 and 68 at Sawgrass and three sub-70s at Colonial, while he also qualified for the US Open to again demonstrate that the game which earned him a rookie success on the PGA Tour might not be all that far away.

Of course, there is a case for backing Hadwin at the best of 4/7 available, but he's lost his way a little of late and Hughes' short-game, which again has started to improve, could make the difference. Anything 3/1 or bigger is there to be taken in what should amount to a match.

Top Spaniard

This is another market I like the shape of. Jon Rahm is a solid favourite at a shade of odds-on generally, but he doesn't appear unbeatable: last year he missed the cut at Erin Hills and though Shinnecock may suit better, I do wonder if his patience may be pushed beyond its current limits.

Sergio Garcia has a good US Open record, but his golf of late has been poor - so poor that he no longer takes up an automatic Ryder Cup spot in the current rankings. Garcia has missed three of his last four cuts and the sole bright spot was 70th place at Sawgrass and it's hard to remember when last his game was this far away from its best.

Garcia has been a touring professional for 20 years now, and 2003 is the only other in which he's missed three cuts in a four-event run. That suggests serious issues throughout the bag and beyond, a combination of adjusting to parenthood, setting new goals and overcoming the humiliation of his Masters defence putting him in no shape whatsoever for this.

Of course, the likelihood is that he snaps out of it soon enough but he's taking up 30 per cent of this book and helps us get 7/2 (general price, 4/1 with BetBright) about the only other runner - Rafa Cabrera Bello.

While Rahm and Garcia are better players, Cabrera Bello is an ideal type with whom to oppose them in that he's consistent and in-form, having played well at Wentworth and in the Italian Open following 17th at Sawgrass, where he was comfortably the pick of the trio.

In the US Open, he's made three cuts in four, the sole failure some six years ago when not the player he is now, and his best pound-for-pound effort this year came in elite company when third at the WGC-Mexico Championship, again ahead of Rahm and Garcia.

Rahm fared best in the Masters and may do so again, but the gap between his price and Cabrera Bello's appears too big.

First-round leader

One that I've mentioned already here but the price is still plenty generous with Sebastian Munoz taken to spring a surprise and lead after the first day's play.

This Colombian hasn't done much to suggest he's a major contender, but did lead the Greenbrier Classic for much of last summer's renewal before Xander Schauffele produced a stunning finish to take the title as he settled for third.

Munoz demonstrated there that he's a deadly putter, never a bad thing in an 18-hole race, and it was the second time in a four-week run that he led after the first round on the PGA Tour.

He's been in similar form recently, leading after day one of two of his last three Web.com Tour starts thanks to rounds of 64 and 65, while also topping the charts in his US Open qualifier which he dominated from the off and sitting seventh in the BMW Charity Pro-Am, a low-scoring Web.com event where he again shot 64.

All told, he's led after the first round of seven of his last 32 starts, a quite remarkable return, and though this is a step into the unknown that is firmly reflected in a general 200/1, with 250/1 available in a spot.

Sebastian Munoz: A habitual fast starter who looks worth a speculative bet

There have been some big-name leaders in the US Open such as Martin Kaymer, Rory McIlroy, Dustin Johnson and Rickie Fowler, but Andrew Landry led the way in 2016, as had Michael Thompson in 2012, and there is room in the frame for an unknown.

Munoz tees off in the first first group going from the 10th tee on Thursday, which means he has fresh greens to go at, but Paul Casey said last year that he felt he gained a real advantage by watching TV coverage before coming out to fire an excellent opening round at Erin Hills, sitting second to Fowler.

Casey is out early this time and remains interesting, however I prefer the claims of Henrik Stenson among the later groups who may gain a similar advantage.

The Swede sits third in first-round scoring this year and while that's largely a reflection of his consistency, he did lead at Bay Hill and sat fourth after the opening round of the Masters at Augusta, a course he'd struggled to crack before.

Prior to a poor start at Erin Hills, he'd been sixth, first and seventh after the first round of the previous three US Opens including at Chambers Bay, where his adaptability to a firm, fast but fairly wide test was on display.

I also like his opening 69 at Pinehurst as a pointer and this former Open champion, who arrives in good form, looks likely to produce the goods. At 40/1 he's also worth backing with the place part comfortably within reach and a solo lead also a possibility.

Others to note here include Tony Finau, who is out in a big-hitting late group and would've been of interest but for a fairly disappointing performance last week, and Phil Mickelson, who has two first-round leads and six further top-10 finishes to his name in this event over the last 20 years.

Finishing positions

It's clear that elite amateurs are getting more and more comfortable in the company of professionals, and that's been in evidence in the US Open.

Since 2010, at least one amateur has finished inside the top 30 every year bar one and that makes Doug Ghim and Braden Thornberry of particular interest, with Paddy Power making them 5/1 and 10/1 respectively for a top-30 finish.

In the more traditional top-20 market, Betfair Sportsbook offer a standout 16/1 versus the general single-figure quotes about Thornberry, yet we can take 33/1 with two firms and 20/1 with various about Ghim.

Ghim is currently top of the world rankings and finished an excellent 50th at the Masters, leading the way among the amateurs, and bet365 only give Thornberry narrow preference (4/1 versus 5/1) in their top amateur market.

On the balance of what I know about these two - and that is basically what we can read on the internet - Thornberry might be a marginally better prospect, but there can't be a lot between them while Ghim's Augusta experience has to count for plenty.

And, given that to be top amateur here you're likely to have to finish around 25th, it's worth backing Ghim to go just a shot or so better and sneak a top-20 finish at 33s, with anything down to 20/1 considered acceptable.

Also worth mentioning is Theo Humphrey, who is 12/1 for a top-20 finish with some yet 50/1 with Unibet and 888sport. He's 10th in the world and it's far from the worst approach to back more than one amateur to force their way onto the first couple of pages of the leaderboard.

We're increasingly close to seeing one of them have a chance to win a US Open come Sunday, something that has happened more than once in the Open Championship recently, and the best way to take advantage may be to go high on their finishing positions.

Posted at 1100 BST on 12/06/18.