Finding that magical place where winning majors feels like another day at the office is the eternal quest for the game's best players.

Rory McIlroy is battling to rediscover that Midas touch. So too is Jordan Spieth and while the Texan shot a four-under 66 to move into the early clubhouse lead on five-under-par in the US PGA at Bethpage Black, finding that comfort level is harder to rediscover once it goes away.

Pádraig Harrington, who followed a 75 with a 77 to miss the cut comfortably on 12-over par, knows how to feels to have that ability to take punches and know you will bring back up from the canvas.

"When you are winning majors like that, you get to a point where you are comfortable that your game is good enough," Harrington said the bulletproof feeling that Brooks Koepka enjoys when he tees it up in a major these days. 

"He didn't come in here thinking he had to play great to win. He came in thinking that if he could play like Brooks, it would be close enough.

"Tiger used to say his B game was good enough to win. If you say that, your A game turns up. If you think you need your A game, your B game turns up. 

"That's the way golf is. When you are winning, good things happen, and you are able to handle adversity and take a few punches. Two or three years ago, Jordan nearly birdied every hole after he made bogey. How easy is golf that way? 

"It's momentum, and Brooks clearly has that at the moment. He doesn't feel he has to do anything special.

"Rory was like that. Rory had an advantage in 2011. He knew turning up that if he played his game, he was going to win. Now he turns up and he's looking over his shoulder wondering how other guys are going to play."

Spieth's comfort came from his ability to hole putts from everywhere, and he rediscovered that touch at Bethpage yesterday, making 141-feet of putts in a 66 that puts him in the frame to at least have a chance of completing the career grand slam this week.

“The putter is certainly better now," Spieth said after finishing the day on five-under par, one stroke clear of Daniel Berger, who shot 66, and world number one Dustin Johnson, who posted a 67.

"It feels like I'm playing the way I'm scoring, which is really nice. I'm seeing tighter targets the better I'm hitting it; and therefore, I'm standing on tees willing to take on draws when there's trouble right and just knowing how to get the ball drawing and missing left, if anything.

"I still need to hit more fairways. Just like I said in here on Wednesday, I've got to be playing out of more fairways to be able to do—I made a lot of putts, and I can't necessarily rely on that."

As for the grand slam and the chance to become just the sixth man to pull off that feat, he said: "If I'm able to put some good work in tomorrow, then I will be in contention on Sunday. And at that point, it will be just more of trying to win a golf tournament.

"It won't matter to me what tournament it is. I'll be pleased to be in contention, knowing that the work I put in from being pretty far off has really come back nicely on a very difficult golf course.

"I imagine that will take pretty much most of my thought, but I mean, we'll see. I'm not sure what to expect."

Now 47, Harrington knows that he needs to be perfectly prepared to contend in majors and having only returned to action six weeks ago after breaking his wrist before Christmas, he was disappointed with the way he prepared for this week.

"Ten years ago, I was within my comfort zone,” said Harrington, who mixed two birdies with five bogeys and two double bogeys yesterday. "Now I am on the edge. And when you are on the edge, you just don't want to make a mistake. And so more mistakes happen.

"When you are good, you are still making those mistakes, but you are able to take a few more punches."

He enjoys watching others trying to work the game out, but he's not seeing anything new and even with all his experience, he was caught out this week.

"Guys think there are different, but they are not," he said. "Basically history keeps repeating itself when it comes to golf. We get sucked it at times, but in the end, we have seen it before."

As for his own game, Harrington feels as though he is only just emerging from his off season and with two weeks off to come, he plans to work hard to be ready for the RBC Canadian Open rather than thinking ahead to The Open at Royal Portrush.

"It's like it's January for me," he said. "My game was well and truly mixed up this week. It doesn't catch up with you at a normal event but you come to a big event like this, and it does catch up with you.

"I'd give myself a Z for preparation. It was very, very poor and it got shown up. At 47 years of age, you'd think I'd know better. The only good thing is that sometimes you need to be taught a lesson to get motivated to do the right things. 

"If I pushed out my preparation for Portrush in two months' time, I'd probably get lazy. So I have got to start now to get ready for Canada. And if I get ready for Canada, maybe I might be ready for Portrush."