All of the above were clearly on the right side of the draw for the first two rounds having started on Thursday afternoon and early yesterday when expected downpours did not arrive until late morning, towards the end of their rounds. Defending champion Zach Johnson was another treated kindly by the draw, following his opening 67 with a one-under 70 to occupy fifth place at five under on a leaderboard that was not threatened in the afternoon wave as the winds strengthened and heavy rains returned to Royal Troon.

Shane Lowry described the conditions as he reached the 16th tee as “horrendous, like the worst weather you could get” as he was unable to build on back to back birdies at the start of his round, giving those shots back at the 13th and par-five 16th for a level par 71 that kept him at seven over for the tournament and consigned to a weekend off alongside fellow Irishman Paul Dunne.

Of golf’s so-called big four, only morning starter Dustin Johnson broke par, a 69 moving the US Open champion to two under, level with McIlroy. World number one Jason Day will start the third round 12 shots back of Mickelson at two over par following a level-par 71 while Jordan Spieth, third in the rankings, just scraped into the weekend on the cutline at four over after a day to forget with the putter and a round of 75.

McIlroy was another such victim of circumstance, although he had started so brightly with birdies at the second, sixth and seventh to reach four under par that it seemed possible he might buck the trend and make further inroads to Mickelson’s lead. The round started to unravel however, the four-time major winner bogeying the ninth and then adding woe upon woe at green after green as birdies and, crucially, pars went begging. Bogeys came at the 10th, 12th and 13th as he began his return to mid- division, only a birdie at the 16th lifting the mood as McIlroy carded his 71 to start today’s third round exactly where he started the second.

“I’m eight shots back. I’m trying to be as optimistic as I can, I guess,” McIlroy said. “I can draw on memories of being in similar positions going into weekends and having won. But this is a little different. It’s the Open Championship and the conditions are a little tougher.

“But, yeah, I’m optimistic. I feel like I’ve played well. I think that’s the great thing. It’s not as if I haven’t played well. I’m in this position of I’ve played very well, so I’m happy with that.”

Mickelson, the 2013 champion, remains the man to beat and believes he is playing some of the best golf of his glittering career, a sentiment endorsed by his opening rounds of 63 and 69 for a 132 that represents the lowest first 36-hole total at Royal Troon in an Open, eclipsing Darren Clarke in 1997 and Bobby Clampett in 1982.

Having laid the foundations with that sparkling 63 in the sunshine on Thursday, narrowly missing out on a majors-record low round of 62 when his final putt lipped out, his second round in more difficult conditions as heavy rain arrived at the Ayrshire coast in mid-morning was described as “stress free”.

“I thought it was a good round to back up the low round yesterday,” Mickelson said. “I played kind of stress-free golf again. I made one or two bad swings that led to bogeys. But for the most part kept the ball in play and played kind of stress-free golf.

I don’t feel the pressure like a lot of players do to try to win the Claret Jug because I’ve already won it, and that takes a lot of pressure off me. The desire to capture that Claret Jug puts a lot of pressure on. The fact I’ve done it relieves some of that. I would love to add to it, but having already done that was big.”

Teeing off on both days in the group ahead of Mickelson, Graeme McDowell had the chance to see some of Mickelson’s excellent play at close hand. As the Portrush golfer began his wait to learn whether he had made the cut having finished 36 holes in four over par as the afternoon wave of starters began their trip into the unknown, McDowell, said of the leader: “He’s been showing as much quality the last couple years consistently as he has in a long time. It’s not surprising he’s doing as well as he is because he can really kind of make the most off the scrambling here at this golf course. He’s obviously controlling his golf ball well.

“I got to be honest, I knew he was going well yesterday but he came with a great sail later on, and obviously nearly shot 62. I knew it was going well, but didn’t know it was going that well. Keeping a bit of an eye on him there today.

“I think you only have to look at Phil’s stats here in 2004. He shot 74 I believe in the first round in the best conditions and rallied to finish second or third or wherever he finished. So he feels fairly comfortable in this golf course.”

As the afternoon progressed and conditions worsened, McDowell will have watched the cutline come back to him and then pass him by along with the likes of Spieth, Masters champion Danny Willett and Colin Montgomerie, all of whom now get to hang around a couple more days. With former champions Pádraig Harrington and Darren Clarke comfortably into the weekend rounds, on level par and one over respectively, Ireland have four standing in the oldest tournament of them all. Alas the quartet’s chances of adding a 10th major title to their tally seem fairly remote.

This story first appeared in the Irish Examiner.