Steve Kerr of the Golden State Warriors speaks at the press conference after his teams 129-120 victory over the Cleveland Cavaliers in Game 5 to win the 2017 NBA Finals. Thearon W. Henderson/Getty Images

Last night, the Golden State Warriors faced a tense situation, eerily reminiscent of the 2016 NBA Finals: They were up 3-1 against the Cleveland Cavaliers going into Game 5 at Oakland's Oracle Arena. The last time that happened, the Cavs came back to win it all.

The pressure was on for Warriors coach Steve Kerr, who sat out most of the playoffs due to health issues related to a back surgery gone wrong. Kerr returned to coach the team in Game 2 after interim coach Mike Brown went 11-0.

Neither Kerr nor his team buckled under the stress — their "death lineup" took down the Cavs 129-120.

A 1972 book may be partially behind Kerr's ability to deal with the high-pressure situation so gracefully. The coach has repeatedly discussed the lessons he learned from Timothy Gallwey's classic text "The Inner Game of Tennis: The Classic Guide to the Mental Side of Peak Performance."

The nonfiction book offers key lessons for instances in which the anxious brain might sabotage whatever you are trying to accomplish. Gallwey examines the relationship between the body and mind, informed by Zen Buddhism, and seeks to help readers understand how to stop their mind from getting in the way of their bodies.

It's essentially about the practice of mindfulness — quieting your thoughts and not judging every moment so that you can let your body do what it knows how to do.

As Gallwey writes in the introduction:

"It is the thesis of this book that neither mastery nor satisfaction can be found in the playing of any game without giving some attention to the relatively neglected skills of the inner game. This is the game that takes place in the mind of the player, and it is played against such obstacles as lapses in concentration, nervousness, self-doubt and self-condemnation. In short, it is played to overcome all habits of mind which inhibit excellence in performance."

Kerr is a serious reader with some great book recommendations, but when he sat down with Sports Illustrated writer Chris Ballard last year, the discussion soon turned to "The Inner Game of Tennis." The book has had such a huge impact on Kerr, he said, that he usually keeps multiple copies of it because he gives them away so frequently.

Kerr isn't the only devotee of the book — Seattle Seahawks coach Pete Carroll is a huge fan and wrote the forward to a recent edition. And New England Patriots quarterback Tom Brady has also posted quotes from the book on Instagram.

💧 A post shared by Tom Brady (@tombrady) on Jan 19, 2017 at 9:30am PST Jan 19, 2017 at 9:30am PST

According to performance expert Brad Stulberg, author of the recent book "Peak Performance: Elevate Your Game, Avoid Burnout, and Thrive with the New Science of Success," the 45-year-old lessons in the book are largely backed up by psychology research today.

"[N]ow-emerging science supports nearly all of its insights, many of which, like how to thrive in unsettling times, are as relevant as ever," Stulberg wrote for New York Magazine. The chief lessons in the book — namely that you can't force relaxation, should stop obsessing, and must choose action over thinking about action — are all relevant now, both for sports and life in general.

"The overarching lesson of 'The Inner Game of Tennis' — that we need to get out of our own way — is simple yet profound," Stulberg wrote. "There are immense benefits to muting the judging Self-1 so that we can get more in touch with the doing Self-2. If we tune into and lead with our bodies, they have lots to tell us. After all, 'they' are us."

This applies to playing, coaching, and more.

As a team, the Warriors have earned a reputation for developing mastery by working on the mental side of the game. That makes sense — in any high-pressure competitive athletic situation, the difference between success and failure is frequently a question of mental readiness.

Last night, Kerr and the Warriors' powerful lineup showed they were ready.