JOHNS CREEK, Ga. -- Had he known the putt was for history, perhaps Steve Stricker would have grinded over it a bit harder, produced every last ounce of effort.
Then again, maybe Stricker's ignorance as it pertains to the game's greatest records serves him well, keeping him from pressing and getting too caught up in all the details.
Stricker, 44, is America's highest-ranked player in the world, a player who rebuilt his game after mid-career crisis but one who has yet to win a major championship.
He got off to a good start in that regard Thursday at Atlanta Athletic Club, taking the first-round lead with a 7-under-par 63 that matched the lowest round in major championship history.
Stricker had a 10-foot birdie putt on the ninth green, his last of the day, but was unaware that if the putt fell he would be in the record books alone -- until his caddie, Jimmie Johnson, told him afterward.
"I was like, 'Shoot, it was?'" Stricker said. "It never really registered. I was just trying to make a birdie and finish 8 under, and I really was concentrating on the putt but never thought about the history part of it."
If there is one thing Stricker has learned over a career of ups and downs, it is that it makes no sense to put more pressure on yourself than already exists.
"I try to downplay it," said Stricker, after taking a 2-stroke lead over fellow Wisconsin native Jerry Kelly. "I keep trying to tell myself it's just like any other tournament, we're playing against the same guys we play against on a weekly basis.
"Try tricking yourself into thinking that there's really nothing extra or different about this event ... knowing deep down there is. That's the trick."
There is nothing much tricky about the 7,467-yard, par-70 course that Stricker dismantled. It has long par-4s, a 260-yard par-3, difficult rough and a brutal finishing stretch of holes.
Tiger Woods, the last player to shoot 63 in a PGA Championship, played his last 13 holes in 10 over par and shot 77.
Ryo Ishikawa, who on Sunday was in contention at the WGC-Bridgestone Invitational, had five double-bogeys, no birdies and shot 85.
U.S. Open champion Rory McIlroy looked as if he was ready for a boxing match after taping up the wrist he hurt when he swung his club against a tree root.
The heat and humidity was enough to drain all of the Guinness right out of British Open champion Darren Clarke.
Yet there was Stricker, who practices in the Madison, Wis., winters by pounding shots from a heated practice bay into the snow, getting hot in the steamy conditions and making seven birdies and no bogeys, including a rare birdie at the par-3 15th that played to 254 yards.
"You have to play from the fairway here," said Stricker, who hit 9 of 14 fairways but was in the first cut a few times as well. "I don't care if you're long or short, it puts a premium on playing from the fairway. Some of the drives I missed today, I ended up in some pretty decent spots."
Stricker has won eight of his 11 PGA Tour titles since turning 40, including two this year at the Memorial and the John Deere Classic.
His Memorial victory made him the top-ranked American, and he is now fifth in the world -- although there's that major championship void.
Really though, Stricker has rarely been a contender in the game's biggest tournaments. His best finish is a second at the PGA 13 years ago, and he has just two other top-5s, none coming since the turn of the century. It's not as though Stricker has been consistently knocking on the door, ready to barge in.
"There's not much left for Steve Stricker to do," Kelly said. "He surprised everybody, and now it's not surprising anymore. Now it's, 'Oh, there's Steve, look out.' Everybody still considers it only a matter of time.
"I think he's been plagued by tough starts, a couple of bad waves, things like that. He's got a pretty good start on it this week, and he's going to be awful tough."
Birdieing the first three holes helped take care of the slow starts, as did perfect scoring conditions in the morning when he played.
And Stricker has certainly shown his toughness in recent years, coming back from a three-year drought in which he wasn't good enough to keep his tour card.
Now he's seemingly unbeatable at the John Deere (three straight victories) and has become a rock of U.S. Presidents Cup and Ryder Cup teams.
Now comes the pressure of leading a major championship.
Stricker will attempt to fool himself into thinking it's nothing more than a regular week on tour.
"Take it easier on myself while playing," he said.
By becoming just the 11th player to shoot 63 at a PGA Championship and recording the 25th such score in a major, Stricker has no reason to beat himself up today. None at all.
Bob Harig covers golf for ESPN.com. He can be reached at BobHarig@gmail.com.