The sign hangs just inside the entrance where the Patriots report to work in the morning: "WHEN YOU COME HERE ... Do your job."
It's a simple reminder that each player must focus on what he, not his teammates, must do that day.
But how well would they do after the way last season ended with a stunning 33-14 first-round playoff loss at home to Baltimore and a devastating knee injury to Wes Welker in the previous game? Tom Brady even said the team lacked mental toughness.
"There's certainly a lot of unknowns going into the season," Belichick said before the final preseason game.
Now everybody knows how good New England is — the first team to clinch a playoff berth, with the leading quarterback in the NFL and an offense that steamrolled its last two opponents, 45-3 and 36-7. Its 11-2 record is tied for the league's best.
With Belichick and Brady, together for their 11th season, the three-time champions always have a chance to be contenders. This year, the speedy progress of youngsters and the seamless integration of in-season pickups have made them formidable.
Randy Moss traded? These Patriots don't miss the mercurial deep threat now that team-first receiver Deion Branch has scored on pass plays of 79 and 59 yards on two of his 44 catches since his trade from Seattle after four games.
"They just look like kids out there having a good time. There's a karma and a chemistry with this team that's pretty special," said Robert Kraft, who has owned the team since 1994. "I think what's evolved over the last seven or eight games is there's a sense of confidence and the locker room is a very positive atmosphere."
The Patriots have won their last five games with a 13-0 turnover margin thanks to well-disguised defensive alignments. They're first in the NFL, scoring 31.9 points per game. And their leader, Brady, has the best passer rating in the NFL, not to mention 29 touchdown passes overall, and no interceptions in his last eight games.
Not too bad, huh?
It would be easy for the players to get carried away going into Sunday night's game against the Green Bay Packers (8-5), who may be without quarterback Aaron Rodgers. He suffered a concussion last Sunday.
"Tom said it best: 'Stay humble and stay hungry,'" defensive end Gerard Warren said. "That's our approach."
The Patriots weren't about to brag about the first half of the season. They beat a bad Cincinnati team 38-24, lost to the New York Jets 28-14 and edged Buffalo 38-30. The next week they trailed Miami 7-6 at halftime, then capitalized on Dolphins mistakes, scoring touchdowns on a blocked field goal and an interception for a 41-14 victory.
After a bye, the Patriots took another big step by hanging in with, and beating, two solid teams by the same 23-20 score — in overtime over the Ravens team that routed them nine months earlier, and over San Diego on the road.
Mentally tough? No question about it.
"It's changed," Kraft said Tuesday. "We've had the privilege of getting out ahead the last few games and then really turning it on and that makes a difference. But when the games are tight, and you have to just stay there (and play) strong in the fourth quarter," that shows determination.
The rookies picked that up as the season has gone along, gaining confidence and comfort. Tight ends Rob Gronkowski and Aaron Hernandez have been outstanding, cornerback Devin McCourty is second in the NFL with six interceptions and linebackers Brandon Spikes and Jermaine Cunningham have made strong impacts. Former free agents BenJarvus Green-Ellis and Danny Woodhead have revitalized the running game and improved a diverse offense that baffles defenders.
All have been coachable and consistent, the Patriots way.
"It's all about buying in from the first day that you walk into the organization," tight end Alge Crumpler said. "If you want to be on your own program, you'll be out of here real quick."
The win in San Diego put the Patriots at 5-1, but they still had some growing to do. They beat Minnesota 28-18, but then were upset 34-14 by the Cleveland Browns, who entered at 2-5.
"Maybe that was waking up a little bit," cornerback Darius Butler said. "We've been paying a lot more attention to detail" since then.
Players blamed the loss on a bad week of practice, a lack of focus that carried over to the game. They vowed to change.
"It's going to be a different team," Branch vowed the day after the setback. "I'll tell you right now."
He was right.
The turnaround was immediate: a 39-26 win over the tough Pittsburgh Steelers in which the Patriots led 23-3 after three quarters. And then a 31-28 victory over the Indianapolis Colts sealed by an interception by James Sanders at the New England 6-yard line as Peyton Manning was driving for the winning touchdown in the final minute.
The Patriots had learned their lesson from the playoff loss to the Ravens in which Brady's three turnovers led to a 24-0 first-quarter deficit — start fast and avoid mistakes.
"There is a good mix of players in here that really are listening to what our coaches teach," Brady said. Belichick "wants us to be a smart, tough, physical football team that plays well under pressure. We listen to the best coach of all time. Hopefully, you learn something."
Since beating the Colts, the Patriots have been nearly unstoppable, scoring on 18 of their last 26 possessions with Brady throwing 10 touchdown passes. A year after getting off to a so-so start, when he was coming back from a season-ending knee injury in the 2008 opener, the former NFL MVP and three-time Super Bowl champion may be playing as well as ever.
"He is such an outstanding leader," Kraft said. "The real brilliance ... is the way he can read defenses and see where the opportunities are and then put the ball in places where only our receivers can catch it."
The remaining three games are at home against Green Bay, on the road against Buffalo (3-10) then back home against Miami (7-6).
"Coach (Belichick) always puts it best to us," Brady said. "He says everything that's happened this year has just provided us with an opportunity. There is nothing set in stone. Yeah, we're in a good position, but we can be in a bad position really quickly."
All the buzz about another MVP award? Brady doesn't want to hear it. The chatter about a fourth Super Bowl title in 10 years? Forget it. It's all drowned out by Belichick telling his players what they did wrong even in lopsided wins. Again, the Patriots way.
"He holds us accountable on every single play and every single day," Brady said. "He coaches an 11-year veteran quarterback just the same way that he teaches a rookie tight end."
And if the players don't get the message — or if they missed it on the sign when they arrived for work — they can read it when they leave.
"There's a sign when we walk out the door every single day, the only door we can go out of this building as players," Crumpler said. "It says, 'Ignore the noise, manage expectations.' So I think it's simple enough. Big, bold letters."
The Patriots way.