Its reputation had gone before it and its reappearance in the European Tour didn't disappoint. As one of the most famed and feared links on the planet, the course at Royal County Down – designed by Mother Nature and a myriad of architects who added their touches to Old Tom Morris's original layout over the years – was, as Rory McIlroy described it, akin to a game of chess. The challenge is mental, as much as physical.

The first two rounds of the Irish Open have contrived to test all facets of the game, and the logjam atop the 36-hole leaderboard – six players on 139, three-under-par – has only served to underscore the belief that the conundrum is one that takes some unlocking.

With weather fronts of heavy cloudbursts materialising and disappearing only to be replaced by periods of sunshine and a stiff wind blowing across the links, players who have allowed their minds to wander at all have been severely punished.

Victim

Pádraig Harrington, who has assumed the role of leading Irish player, was one such victim, a run of three holes after the turn in which he went bogey-double bogey-bogey damaging his title aspirations.

Yet, even so, he remained very much in the thick of it all. A second round 73 for 140 meant the Dubliner reached the midpoint stage just a shot adrift of the leading sextet. He is very much in contention, as is Luke Donald, who joined him a shot adrift.

In all, six Irish players managed to survive the cut: Harrington (140), Paul McGinley (145), Shane Lowry (146), Simon Thornton (147), Darren Clarke (147) and Graeme McDowell (147). But there was disappointment for tournament host McIlroy, who couldn't recover from the damage inflicted by his opening round 80. His role for the weekend will be to appear by the 18th green Sunday to present the crystal trophy.

On yet another challenging day on the links, with black clouds arriving intermittently around Slieve Donard to douse the course with rain, some players found the challenge too tough. One three-ball disintegrated in its entirety as Raphael Jacquelin and Alvaro Quiros joined the already absent Simon Dyson – who withdrew on Thursday – as casualties.

Unlucky 13

Jonathan Moore, who arrived with memories of his winning eagle in clinching the Walker Cup in 2007, departed with something to forget: the American ran up a horrendous 13 on one hole, the 13th, in which he lost three balls off the tee before finally getting a shot into play. He promptly lost another ball with what constituted his eighth shot and eventually ran up that 13 in recording a second round 86 which left him isolated at the very end of the field.

There were some big name casualties apart from McIlroy. US Open champion Martin Kaymer – who defends his title in Chambers Bay next month – improved on his first round by 10 shots, a 69 to follow his 79, but missed out by a shot; Italian Matteo Manassero was 10 shots worse, an 81 to follow his 71, to also miss out; and former British Open champion Paul Lawrie included an eight – known in the trade as a snowman – on the 16th in departing early.

As Graeme McDowell described the challenge put up to players: “When those squalls are running through, it is brutal, it really is.” Too tough? He shook his head. “The course is what it is, it is a difficult golf course. It’s a tough course played in tough conditions.”

In fairness to McDowell, he stuck to his task and a birdie on the 18th, his closing hole, gave him further game time for the weekend. He survived on the mark. “I feel like I’m turning the corner with my game, it’s important to get four rounds in.”

Hardships

For Harrington, it had all seemed so easy for so long and he actually opened up a three-stroke gap on his nearest pursuer when he birdied the first hole, his 10th of the day.

After that, having lived in a world of his own for 28 holes, oblivious to the hardships endured by others, he was brought back to reality with a bogey on the second that was followed by a double-bogey six on the third and a bogey on the fourth.

Then, after getting back on track with a birdie on the 16th, he returned to his chasers with bogeys on the 17th and 18th.

“What I went through over the last six or seven holes is what most of the players are going through all the time, so I feel bad. It seems to be the way that most of the course is playing for most of the guys. Hopefully, I won’t do it again over the weekend. Hopefully, I’ve had my bad run.”

A finish of birdie-bogey-bogey left mixed emotions for Harrington.

“I’m disappointed with the way I finished . . . I did get a bad run on the back nine and I am disappointed at letting the rest of the field back into the event. But I am still in a strong position going into the weekend. I still need to play well on the weekend, I need a big weekend, but certainly I would have taken this at the start. I have to play well and stick in there and hopefully not get many bad breaks,” Harrington said.

Harrington will have to roll up his sleeves for the weekend’s challenge. No better man to do so, especially in tough conditions.