Brooks Koepka tees off on the 17th hole during the first round of the PGA Championship. (Julio Cortez/AP)
Columnist

It’s the simplicity of Brooks Koepka that’s so intimidating. He’s a direct, uncomplicated, solid man, the kind who seems as if he’d be handy with a wrench — and capable of bringing it down on your head.

Golf is a straightforward game, the way he’s playing it. Watching him, you suddenly remember that it’s just a matter of swiping at rocks with a stick. He ratchets back and then releases, and blam, the ball is flushed 320 yards down another fairway. No overswing, just the raising and lowering of those heavy instruments he calls arms, letting the weight of them do the work, and clubbing another major championship field into the dirt.

If there was a thought bubble above Koepka’s head, it would be empty. Blank. Ask him what he was thinking over that final birdie putt in the opening round of the PGA Championship at Bethpage Black, his seventh of the day for a record 63, and he says: “Nothing. Just make it. That was the only thing that was going through my head.”

No monkey-brain worrying over mechanics or swing planes, unlike that thinky targeter Tiger Woods, who was prey to irregular swings that caused a pair of double bogeys. No grinding analysis, like Jordan Spieth with his penchant for considering golf courses algebraically. No puzzling, like poor Rory McIlroy, whose youthful sweet-swinging dominance has dissipated like smoke. No sweating, lashing go-for-broke-ness, like Phil Mickelson.

Koepka owned all of them at Bethpage, with the elementary, deadly, pendulum-like reliability that has become his signature.

Koepka’s percentages at the moment are almost unthinkable for a game that’s supposed to be an unpredictable trial of the soul. He is going for his fourth title in his past eight major championship starts, and he has had five more top-10 finishes. He is on a streak of 10 straight rounds under par in the majors. That’s a simply ridiculous consistency in the face of so many variables and opponents: 156 competitors, not to mention the course, wind, sand, rain and the uncooperative clubs in the bag. Overall since winning the 2017 U.S. Open, he has posted 21 rounds under par in the majors.

“I’m not thinking about tomorrow; I’m not thinking about the next shot,” he said this week. “I’m just thinking about what I’ve got to do right then and there. And I kind of dummy it down and make it very simple, and I think that’s what helps me.”

He makes it seem so uncomplicated. It’s not often you see a player with his brawn and precision. His swing is all neat lines. Look at a freeze frame of his take back and follow-through: His form is as clean and spare as a coat hanger.

“I just keep it very simple,” he says. “I think it’s easier to just — you see the ball, try to make it a reaction sport. Last look, you’re just looking at the target, and you just want to finish it there.”

As for his mental-emotional makeup, he goes about his business with all the expression of a rock formation. One of the most interesting things about Koepka is that he seems so dispassionate. Yet he’s not. He is a reformed hothead, he says in a rare revealing moment, a club-thrower who decided to cure himself of the habit because he didn’t want to show his competitors a weakness.

“I think I’m very stone-faced, very focused, but I also don’t want to give guys an idea of what’s going on,” he says. He doesn’t want “to let anybody know what’s going on in my head, kind of keep it a mystery.”

Koepka is therefore one of the more reserved, unknowable young champions to come along in a while. The audience doesn’t really understand who he is yet. But there is one thing we can know about him. Behind any kind of competitive character is conditioning, the belief that you’ve done enough work on yourself and your game to deserve to win. This is a man who takes his craft seriously. He is not playing this well in major after major after major by accident. This is someone who is looking to create a historical record. Who is clearly trying very, very hard to become a great.

Koepka has let the PGA field in on his thinking about one thing: his conviction that he’s got about half of them licked before they ever tee off. Shortly after arriving at Bethpage, he gave a notoriously frank and confident assessment of his chances of hanging on to the Wanamaker Trophy.

According to his math, “You figure at least 80 of them I’m just going to beat,” he said. “From there, you figure about half of them won’t play well . . . so you’re down to about maybe 35. And then from 35, some of them just — pressure is going to get to them. It only leaves you with a few more, and you’ve just got to beat those guys.”

You could interpret that as arrogant or insulting. Or as Koepka reducing the overwhelming odds to a more a simple, uncomplicated equation.

For more by Sally Jenkins, visit washingtonpost.com/jenkins.