Editor's Note: This story appears in Issue 6 of Golf Digest.

You might not think it right away because I’m kind of quiet and a little under-the-radar out there, but I post a lot of low numbers. I once got around in 60 at the Travelers Championship—when I was a 19-year-old amateur. I’ve finished tournaments at 20 under or better half a dozen times, and in the past three years, I’ve shot 65 or lower about once every six rounds. In other words, I know how to go low.

I might not be widely known for these hot streaks, but I do have a reputation for my stoic approach to the game. Although I average more than 300 yards off the tee, I’d say my reputation among players is more of a thinker than a bomber. My natural disposition is largely unemotional, so I’m pretty deadpan a lot, but that’s not necessarily a reflection of how I feel on the inside. In general, I feel like myself the most when I’m locked in mentally and in work mode.

Maybe that’s because everybody knows I like to read a lot of books. Whether it’s the behavioral economics of Daniel Kahneman in Thinking Fast and Slow or a biography of Paul Newman, I’m only reading things because they interest me. I’m sure I could put together a pretty compelling summer reading list for you from Marcus Aurelius to Ayn Rand, from Lord of the Rings to When Giants Walked the Earth, but no book helped me shoot 61 at The American Express in January or make nine birdies in the final round to win the ZOZO Championship. Understanding Richard Dawkins’ The Selfish Gene (another one of my favorites) won’t win you the member-guest, either.

RELATED: How Patrick Cantlay became one of the best putters on tour

That said, I do believe these books challenge me to think critically about preconceptions. Understanding how you think helps you understand how to play your best golf more often. Sure, there are fundamentals of the swing you need to work on, and I’ve included here a few of my keys to hitting the shots you need to maximize your scoring potential. I’ve learned that playing to your potential is about consistent, controlled aggression. My teacher, Jamie Mulligan, with whom I’ve worked since I was in elementary school, likes to say that I’m really good at seeing what I want to do, whether that is understanding what is physically necessary to make my best swings or what is the smart, purposeful approach to getting the most out of every round. Jamie is a fan of Formula 1 champion driver Lewis Hamilton, and he says Hamilton always drives where he’s supposed to and never where he shouldn’t. That is the fastest way around the track. I want to take the fastest way around my track, too.

In my experience, the fastest way also happens to be the smartest way, even if you aren’t making perfect swings. Playing your best golf doesn’t always mean shooting 60, either. When I won The Memorial in June, I shot 71 on Sunday, and it was a grind. But just as if I was making birdies in bunches, I approached every shot as a singular moment. With the unusual circumstance of going from six shots behind Jon Rahm after the third round to tied for the lead the next morning because of his unfortunate withdrawal, it would have been very easy to get caught up in thinking about how unsettling the situation was and that I needed to approach the day differently mentally. Instead, I went right to work Saturday night getting prepared to hit the shots and make the putts necessary to compete. It was all about taking the new paradigm I was faced with and running with it. When Sunday came, I was committed to investing completely in each shot. It was a real back-and-forth battle, but in the moment, that shouldn’t matter—just like it shouldn’t matter that you’ve just played your best front nine ever. I’d lost this tournament before by trying to force birdies. I won this time by staying patient, being confident and consistent in the work I’d done and the process I have for every shot. You have to stay completely in the present.

Jamie likes to remind me that golf is a simple game if you remember it’s all about hitting shots to spots. One other thing: You can be focused without gritting your teeth all the time. When I won at Memorial, it was intense and maybe I wasn’t smiling every minute, but what I really tried to do on Sunday was to be my own best friend, and the smiles came at the end when it really mattered.

The tips and thoughts on these pages are a foundation for making sure your best golf continues when you’re hitting it well and maybe even when you aren’t making good swings. Some of these are technique ideas that I work on with Jamie to get my swing in a place where the feelings are so ingrained, I don’t have to think much about them when I’m playing. Others are thoughts about the best ways to execute the controlled aggression that leads to lower scores.

When I shot 61 at The American Express or came back in my next competitive round and tied the course record at Pebble Beach with a 62, I remember saying at the end of the day, “That’s as good as I can play.” What I also remember is never saying that, or even thinking that, at any moment during those rounds. No one legitimately thinks, Let’s go shoot 61 today. Playing as good as you can play is not a strategy; it’s a result.

Of course, it’s my job to play the best I can play as often as I can, but if I really think about it, I’m not ever really trying to do that. Ideally, I’m focusing only on hitting the shot that’s required at each moment. Every shot in every great round—or any round—is its own self-contained event. It’s rarely the case that the circumstances should change your thinking or attitude in the middle of a round. Even then, it’s always the case that gathering yourself before every shot is the most effective way to get the best results.

Playing your best golf should be as uncomplicated as you can make it. You’re not activating some special gear or power to suddenly shoot your lowest round. You’ve done the work with your swing and your short game—and probably most importantly your mind—so that when you get to those moments, you’re just executing what you already know.

Maybe that seems obvious, but I’m sure whether you’re a great player trying to win a big tournament or you’re just out for a round with your buddies and you’ve just parred a few holes in a row for the first time in your life, you’re going to experience the pressure that comes in the middle of a good round. All the mental-game experts like to talk about not forcing shots or just letting it happen. That’s useful advice, but it’s not easy. Our thoughts like to get in the way of what the body is trying to do—that’s not just me talking; there’s a lot of research that confirms it.

One of my favorite books is Kahneman’s Thinking Fast and Slow. Its premise has to do with how we make decisions, how we have two internal systems, one being reactive and almost automatic, and the other being deliberate and contemplative. When the two get mixed up, we make decisions that in retrospect get in the way of our success. A perfect example comes in golf when we try to hit a hero shot from a bad position, which only leads to compounding the error. This is not exclusively a physical mistake. It’s a physical mistake brought about by a much larger mental miscalculation. We make an emotional decision because it’s easier, and because it’s easier, we convince ourselves it’s the right one. Kahneman likes to point to what he calls “biases of intuition,” and he writes, “We are often confident even when we are wrong.”

What Kahneman’s book showed me isn’t just that our intuitions aren’t always right, it’s that we need to be aware of how that internal process is happening because then we can control it and use it to produce the best results. It is not easy to manage the two thinking systems Kahneman writes about, especially under stress when we want a fast answer in a situation that requires slow thought. Even worse, he writes, “we can be blind to the obvious, and we are also blind to our blindness.”

The goal is to be disciplined, at least selectively. Maybe something as simple as walking slowly but purposefully will help keep your mind from racing into bad thinking. As he writes, “learn to recognize situations in which mistakes are likely and try harder to avoid significant mistakes when the stakes are high.” In golf, this means there are “good bogeys.”

The way our minds like to complicate things is one of the great challenges of golf. Unlike a lot of other sports, it’s not reactive. There is no opponent. That also means you can have control of how you approach every shot. I’ve always thought that all the prep you do before a tournament or before a round is more important and defines how you’re going to approach that shot and make that swing. Just showing up and somehow switching it on isn’t really my style, and I don’t think it breeds consistent success.

If there’s a reason that I don’t get outwardly excited all the time, it might be because I believe I’ve done the work I needed to do, so positive results are expected. Your best golf starts well before you get to the first tee and obviously well before the point where you’ve played a good front nine. All the actions that led you to that point are just as important as the point itself.

It’s why I wanted to learn what the good players Jamie worked with at my home course in Southern California, Virginia Country Club, were doing to be good—even when I was 10. Long before I read The Selfish Gene, I understood that your best is kind of preordained—inextricably tied to your genetic makeup, sure, but only optimized if you put in the right work. You play great because of who you are, what experiences you have and what you decide to do with all that in the moment. It’s why golfers are much better now than they were 50 years ago, or probably even 10 years ago. The process of improvement increases exponentially. The starting points are so much more advanced. That’s why I have to believe that the trendline is for me to continue to get better, at least up to a certain physical, chronological point. It’s like what Dawkins talks about with genes in his writings about evolutionary biology. We all are carrying the best genes forward to the next generation, and he calls us “survival machines.” I think it’s more like we’re big “gene preservation machines,” but the point is the same. The natural direction of everything is toward improvement. Dawkins’ book helped me realize that it’s not accidental or random. It is directly attributable to specific developments. It’s why I can feel comfortable going for a par 5 in two, hitting a fairway-finder tee shot or clipping a chip shot off a tight lie. I know I’ve done it before; I know I’ve made that swing; I know I’ve accurately assessed that situation. I don’t just think I can, because just thinking it is a wish. If you’ve done the work, you know the shot, and the shot is its own event that you’ve hit already.

Dawkins once wrote about how he thought differently about the early theories on evolution, that it wasn’t this series of random occurrences that led to a survival of the fittest species. “Chance,” he wrote, “is just a word expressing ignorance. It means, 'determined by some as yet unknown, or unspecified, means.’ ” If you understand and analyze why things happen in a round of golf, to me it’s not about bad breaks and good breaks. Everything can be explained. When you have those analytics as a foundation, you understand that the work you do to get ready to play your best golf, the physical and the mental, is precisely how you play your best golf. The more consistent your approach to that work, the more often your best golf will be the result. There is a logic to it, and not only that, there’s a compounding effect. Your best golf breeds more confidence and more familiarity with what it feels like to be playing your best golf, which in turn leads to more of your best golf.

Your experience tells you that you’re not going to play perfect all the time, so you have to continue to work hard and not get overwhelmed by frustration when things aren’t going your way—even though you feel like you are putting good work and time in. When things go your way, be open to it, and do not let the bad results mess with your approach. It’s obvious that you can hit great shots and make bogeys. I’ve had a number of weeks where I played better and lost than when I’ve won (I shot 126 on the weekend at The American Express and lost; I shot 22 under at Medinah in the BMW Championship and lost by three shots.) For me, you have to maintain a certain level of confidence to make sure you’re able to capitalize on opportunities when they present themselves. Experience is just as much a contributor to success as is practicing bunker shots. That’s why I think hitting a bunker shot in an actual round probably helps you play better the next time. So practice with a purpose, for sure, but play with purpose, as well. That experience of making good swings should be prominent in your mind when the internal pressure starts to mount as you come down the last few holes with a chance at your lowest score ever.

There shouldn’t be anything spooky about that moment. I want you to feel like you should hit good shots because that self-knowledge gets exponentially stronger with each example of supporting evidence. In the end, playing your best and shooting a low round is about everything you’ve done leading to that moment. What you do, how you do it and most importantly how you process it all—the successes and the failures—set up what happens in that moment. That comfort is where controlled aggression comes from.

I said at the beginning of this that no one realistically goes into a round thinking about setting the course record or posting a personal best. I see that in the great biographies I’ve read, like General Patton’s or Winston Churchill’s or even Paul Newman’s. He didn’t decide one day that he was going to be the most famous actor in the world or an elite race-car driver or the head of a $500-million food company or an epic philanthropist. He learned throughout his life to be in complete control of his direction, his attitude and his progress toward improvement. He learned not to waste time with things that didn’t benefit that direction. I admire his resolve. A biography I read called it like this: “He made decisions about what movies to make and how to present himself to the world in the same way he made decisions about his performances and race cars and salad-dressing recipes: studying, mulling, checking his instincts, and, finally, paying careful attention to his gut. There was serendipity to his career—luck, coincidence, happy fortune—but there was also hard application and righteous effort.”

All that is definitely true about playing your best golf in one round or all the rounds you have left. I also remember what I learned from another self-made superstar of the ’60s, ’70s and ’80s. Mr. Nicklaus told me a few days before my 64 in the final round to win The Memorial in 2019 that I needed to enjoy the experience of playing great golf more. He said, “You need to go out there, have a good time. Look around when you’re out there. Look at all the people having a great time. And then you need to have a great time and realize that’s why you’re there— relax and go have fun.”

That might be the best advice of all. He should write another book. I’d read it. —WITH MIKE STACHURA