His consistent approach to preparation for the next opponent, whether a powerhouse or a pushover, is the cornerstone of the coaching that has brought the New England Patriots to their fifth Super Bowl in 11 years.
The more intense the practices, the more prepared his players are for the game.
"You know what to expect week-in and week-out with him," wide receiver Matthew Slater said. "The attention to detail is always there. It doesn't matter if it's a bye week or if it's a divisional playoff round. He's committed to winning and that commitment never falters, no matter what the circumstance, no matter how much success we've had or how many games we may have lost in a row.
"That commitment to winning is always there."
During practices, Belichick strolls the field, sometimes twirling his whistle on a lanyard, other times stopping to talk with players. His daily message is simple — get the fundamentals right and just do your own job while preparing for the uniqueness of the next opponent.
That's resulted in 10 straight victories, eight in the regular season and two in the playoffs. Another win on Feb. 5 against the New York Giants would give the Patriots their fourth Super Bowl championship.
"I think every game is a big game," Belichick said Tuesday. "Every time we get an opportunity to compete then we try to take advantage of the time leading up to that opportunity — the practice week, the preparation, the film study, understanding our game plan and our adjustments, all of those kinds of things.
"What else is there to work on but the game, the next one on your schedule, the one that you're playing? You try to cover all your bases for that game, you play it, and then you start the process all over again with the next one."
Right guard Brian Waters played his first 11 seasons with the Kansas City Chiefs. But when he signed with the Patriots on Sept. 4, eight days before the season opener, he quickly sensed the difference in Belichick's style.
"I wasn't here in training camp but, from day one, I can tell that he's all about the details," Waters said. "He's all about everybody doing their own job and staying in their lane. Everybody has their own responsibilities. That's something that you learn early on and that's something that he still makes sure that we understand today."
Another part of the Belichick playbook: Don't focus on the past or far into the future, just on the next practice and the next game.
That's a big enough workload, considering how hard he pushes his players.
James Ihedigbo didn't start a game the past three seasons with the New York Jets, but did go to AFC championship games the past two seasons. The Jets lost both. This season he started 12 of 16 games at safety for the Patriots and reached the Super Bowl.
The Patriots are special, he said, "because we prepare. We prepare harder than any other place that I've played and it definitely gets you focused in on your opponent and knowing them and understanding their strengths and how they want to attack you.
"So that's what we're keyed in on this week."
And this season's playoff wins over Denver, 45-10, and Baltimore, 23-20, are fading rapidly from players' minds.
"It has been going on all year and you just have to put everything in the past," tight end Rob Gronkowski said. "If you have a good game, that is all over with and you just have to keep moving on forward to the future and make sure you have a good practice week."
Running back Stevan Ridley, drafted in the third round last April, was the team's second-leading rusher during the regular season. When the playoffs began, he didn't notice much difference in Belichick's intensity.
"You know coach Bill, man, every game is serious," Ridley said, "playoffs, regular season, preseason."
What stands out most about Belichick is his "consistency, just his ability to stay focused to the nth degree and do that repetitively, week-in and week-out," Light said. "It's not an easy thing, obviously, running a team and putting up with a lot of guys like myself and the rest of the knuckleheads in that locker room.
"But you know what? I think that coming in and setting that example with our entire coaching staff and how he approaches everything, it makes it easy for all of us to fall in line."