FOXBORO — For the Patriots, their Nov. 7 defeat to the Browns in Cleveland has become a cautionary tale — ample evidence that no matter what your record might be and who’s on the opposing sideline, you simply can’t roll out there with a subpar effort and expect to win.

Defensive lineman Vince Wilfork said Wednesday the loss to Cleveland provided the sort of “gut-check” the team needed — since then, the Patriots have won six straight and scored an average of 38 points per game.

“I’ll tell you what: Cleveland was a wakeup call for us. They put it to us,” Wilfork said. “I don’t think there is one guy who left that game happy with anything he did that day. And I think we came together as a team and started putting more emphasis on little things.

“Ever since then I think we’ve just been focused in, and one of our goals has been finishing, watching more film, watching to see what our opponents do in certain situations. And I think everyone is doing it, not just certain guys, everyone.”

That heightened level of awareness and attention to detail will serve the Patriots well this week as they prepare to face Buffalo in upstate New York on Sunday because a closer look at the numbers reveals that the Bills aren’t your usual 4-10 team. They have lost three games in overtime, and nine of their games decided by eight points or fewer.

And despite the fact that they have been out of the playoff chase the last several weeks, the Bills are unquestionably playing hard for coach Chan Gailey, having won four of their last six — a stretch that would been even better if wide receiver Stevie Johnson didn’t drop a pass in the end zone in a game that eventually turned out to be an overtime loss to the Steelers. According to the Associated Press, only six teams have better records in that span — New England, San Diego, Atlanta, Chicago, New Orleans and Philadelphia.

“They’ve won four of the last six games — how would you say that is?” asked Patriots coach Bill Belichick, responding to a questioner who wondered about the fitness of the Bills. “There’re not a lot of teams that are doing better than that over the last six weeks in the National Football League. Not a lot.”

“They’re playing good football. [They’re] 4-2 in their last six games,” said linebacker Jerod Mayo. “[They] really should’ve won the Pittsburgh game, so they’re a tough team and they’re playing very hard.”

Since their 0-8 start, the Bills have shown improvement in almost every category — on offense, significant gains have come in points per game (18.8 to 20.5), total yards per game (304.6 to 318.3) and pass plays of 25 yards or more (Buffalo has moved from 24th in the league to 13th with 11 in its last six games). On defense, there have been major upgrades in interceptions (from one to nine), opposing quarterback rating (from 108.4 to 73.5) and opponents’ points per game (29.1 to 20).

Are they playing better because there’s no pressure, or is there genuine improvement? The Patriots believe it’s the latter, saying Buffalo has definitely gotten better since the first time these two teams met in Week 3 in Foxboro, a game New England won, 38-30.

“They’re a much better team,” said tight end Alge Crumpler. “They gave us problems the first time that we played them. Since [their] bye week, they’re 4-2. They could easily be 5-1 with the Pittsburgh game, so they’re playing very well.”

On offense, much of the improvement is the result of the continued evolution of quarterback Ryan Fitzpatrick. The Harvard product had his first start of the season in a narrow Week 3 loss to New England, and since then, has really started to come on: He has 2,749 passing yards, 23 touchdowns (including touchdown passes in 15 consecutive games) and 12 interceptions since taking control of the offense.

“He is really a strong man,” Gailey said. “He leads because he’s smart, but he leads by example and the way he plays the game and how tough he plays. He goes and makes a block in, I don’t even know which game it was, but he goes and turns a guy upside down blocking for a run. Those little things like that go a long way in telling your team I’m here not just to stand in the pocket and throw the football around, I’m here to help us win whichever way I can.”

Across the board, Gailey said a lot of the recent improvement comes down to the character of his team.

“I did not see them waiver a lick through those [losses]. Everybody was disappointed. Everybody was hurt, but if you’re not hurt when you lose, you better get out of the business because it does hurt when you lose,” Gailey said. “They came back with resolve to try to go out and find out why we lost, rectify that problem, then go out and find a way to win.”

If the Patriots needed another reason to keep focused on Sunday, there’s always the fact that if they win or tie this Sunday (or if the Jets lose or tie), they will win the AFC East title and clinch home-field advantage throughout the postseason. While New England still has another shot at both if it botches things this weekend, the idea of wrapping everything up with a week left in the regular season is appealing on several levels.

“I think every team wants to control their own fate — that’s what we talk about,” said Crumpler. “And now, we’ve put ourselves in this position. That’s a good thing. Getting this win would be great.”