Sifting through the evidence in search of clues, four obvious candidates for the Open began to emerge.

The suspect, it seems, must be an experienced figure who has contended for big prizes over an extended period and has to have played well enough to make the cut at Castle Stuart, gaining maximum competitive practice over the links without wasting too much emotional energy on battling for the Aberdeen Asset Management trophy.

Two years ago Darren Clarke finished in 66th spot at the Scottish Open then went on to produce his career-defining week at Sandwich. Last year, a solitary sub-70 round was the best Ernie Els could manage on his way to a share of 52nd place at Castle Stuart, yet a week later the South African had played well enough around Lytham to be the man to capitalise on Adam Scott's meltdown and claim his fourth major title a decade after his third.

So, what of their fellow fortysomethings who battled their way to the finish in the Highlands this year? How about, for example, Clarke's colleague in the 2002 Ryder Cup-winning side Niclas Fasth, the hyperintense 41-year-old?

Placed 32nd in the world rankings when he got on to that team, the Swede plummeted to 157th three years later, reached an all-time high of 18th in 2007, then again hit the skids to be 752nd earlier this year.

Despite failing to contest a major championship in five years, he has made it to the Open via international qualifying at Sunningdale in spite of having failed to make a cut since May. Yet the tournament before that run he finished 12th at the prestigious BMW PGA Championship at Wentworth which, along with his three top-10 major finishes and six European Tour wins, goes some way to justifying the claim on the R&A website that: "He has the knack of producing his best golf on the big occasions."

Indeed, on the basis of such past fluctuations of form, a closing 78 here almost ensures that we should consider him our prime contender to follow in the footsteps of Clarke and Els, but there are others.

Take 43-year-old Thai golfer Thongchai Jaidee. He closed with a four-over-par 76 yesterday but has produced five top-10 finishes this season. A best finish of tied for 13th in 17 appearances in majors suggests he cannot make the same claims about rising to the challenge of the bigger events, while only one of his 15 tournament wins, last year's Welsh Open, has been outside Asia.

Perhaps even more unlikely, nine years after his sole European Tour win, would be an Open Championship victory for David Lynn who, in any event, is merely in his 40th year, as he is to reach the landmark in October. Even so, it is curious to note that the closest he has come to winning another event in Europe was at the Iberdrola Open in 2011, the event at which Clarke claimed his first win for three years, offering the first hint of the glories to come later that summer. Lynn's second place in that Spanish event was one of six top-10 finishes in 2011 as he surged to a then career-best 35th in the end-of-season European order of merit. His runners-up berth behind Rory McIlroy at last year's US PGA meant he came 18th in the end-of-season ranking.

Yesterday's winner Phil Mickelson, at 43, is a more obvious Open Championship prospect, and then there's Paul Lawrie, aged 44-and-a-half. Fourteen years may have elapsed since that momentous Open triumph at Carnoustie, but the three European Tour wins he has recorded in the last two years, allied to his crucial Ryder Cup singles success last autumn, attest to his capacity to hold his nerve if he can just warm up that putter a bit.

After closing with a solid one-under-par 71 in yesterday's conditions he admitted to drawing some confidence from what has happened at the Open in the past two years. "Yes, I think I can take more from Ernie's win than anything else," he said. "He's more my kind of age, he's been struggling a wee bit with the putter – and obviously he won at Lytham, which is more of a ball striker's course than a course that you will have lots of putts on. Muirfield is the same. There're not many poor golfers who can win round Muirfield.

"I'm not hitting it awesomely but I'm hitting it well enough to give myself 12 or 13 decent chances of birdie every day – and if you just knock three or four in it makes all the difference. But you know as well as I do that to win a major, to win the Open, everything's got to go your way. You have to get a few breaks, be lucky with the draw and the weather. That plays a massive part. So much of it's got to go right – but if I can hole a couple you never know."