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Patriots coach Bill Belichick lives by this brilliant quote from 'The Art of War'

Courtney Connley

New England Patriots' head coach Bill Belichick is regarded as one of the best leaders in the league.

Under his direction, the Patriots have made nine Super Bowl appearances , including this coming Sunday's game, and have taken home five Super Bowl rings. Belichick also is the fourth head coach in NFL history to reach at least 226 regular season wins .

To keep his team focused, Belichick relies on one key quote that he keeps posted where players can see it.

"The only sign we have in the locker room is from 'The Art of War.' 'Every battle is won before it is fought,'" he told CNBC contributor Suzy Welch in 2017 .

He says the quote from Sun Tzu's military classic captures his philosophy on preparation: "You [have to] know what the opponents can do, what their strengths and weaknesses are ... [and] what to do in every situation."

When Belichick and his players aren't on the field, they're huddled together in practices and team meetings where they spend hours going over films and studying plays. As described by the Patriots Wire , film sessions normally occur the day after a game and they often include Belichick dishing out a few pop quiz questions to keep the players "on their toes."

"It's basically, get ready to learn football," Rob Gronkowski told Patriots Wire. "Get ready to learn the details of every position … You put your learning brain on when you walk in the room. That's what it is, for real."

Former Patriots offensive lineman Rich Ohrnberger described the team meetings as "marathons" that can "last an hour and a half of bad play after bad play after missed tackle after missed blocking assignment after bad pass into a coverage you shouldn't have thrown into."

"I wouldn't describe it as scary," added Ohrnberger. "I would describe it as humiliating, because you realize you had part in potentially the play or plays that lost the football game for your team."

Aside from studying film, Belichick also prepares his players with team bonding activities that include training with Navy SEALs and hosting trivia nights where there is no social media allowed. "Nobody is against [social media] more than I am. I can't stand it," he told Welch. "I think it's important for us, as a team, to know each other. Know our teammates and our coaches. To interact with them is more important than to be 'liked' by whoever on Chatrun."

Belichick told CBS Sports that he still gets anxious before each game. But, he says, "you don't worry about everybody else. You just worry about doing what you can do and make sure you don't screw up what you're supposed to do, what you're responsible for, because nobody else can do that."

At 66 years old, Belichick is not only more than double the age of many of his players, but he is also double the age of the Los Angeles Rams' head coach Sean McVay, 33, who he'll face off against on Sunday. While there has been speculation about when he might retire, the coach tells FOX NFL Sunday analyst Jimmy Johnson that his main focus right now is "just trying to win a game."

"I really like football," he tells Johnson. "I like all parts of it, and it beats working."

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