Patriots Coach Bill Belichick and quarterback Tom Brady talk on the sidelines. With a win at home Sunday over the Bills, New England will seize a first-round bye for the fourth straight season. (Lynne Sladky/Associated Press)

The New England Patriots operated for years like an unholy, inexorable assembly line. They cruised along and cranked out victories, records and the occasional Super Bowl appearance. They made dominance in a capricious league seem easy and smooth; the coach dressed for comfort and the quarterback married a supermodel.

Then this fall happened.

The Patriots are currently held together by ACE bandages, miracle comebacks, baling wire and whatever magic dust Tim Tebow — remember that? — forgot in his locker back in training camp. The defense lost almost a half-ton of defensive tackles to the injured reserve list. Tom Brady’s three best targets from the end of last season are injured (Rob Gronkowski), incarcerated (Aaron Hernandez) and in Denver (Wes Welker). His best remaining receivers would probably be underestimated if they split out wide during a particularly competitive intramural flag football league.

The gears grinded, screws came loose and parts went flying off, and still the machine lurched forward. The upheaval has tested, and ultimately reaffirmed, the wicked football genius of Bill Belichick. The Patriots have clinched their fifth straight AFC East championship, their 11th in 13 years. With a win at home Sunday over the 6-9 Buffalo Bills, they will seize a first-round bye for the fourth straight season.

“Every year is special,” Brady said. “But we really earned it this year.”

Even if he hoisted three Lombardi Trophies, even if he went 16-0 in 2007, this season may stand as Belichick’s finest work. Consider what the Patriots have handled on the way to another 11- or 12-win season. Sunday, humans named Michael Hoomanawanui and Matthew Mulligan played tight end for an offense originally built around Hernandez and Gronkowski. Vince Wilfork, Jerod Mayo, Sebastian Vollmer and Tommy Kelly are out for the year. Make a list of New England’s 10 most indispensable players, and probably half are on injured reserve.

“I think everybody on the team has the same attitude,” Belichick said. “They’ve got to be prepared. They’ve got to be ready to go. You never know when those situations are going to come. You’ve got to be ready for those things. Every team has guys on injured reserve. Every team has players get hurt. That’s the league we’re in. It’s a war of attrition.”

But the Patriots have both faced more attrition and overcome it better than most. Belichick finds players other teams don’t want and makes them useful. Sunday, with left tackle Nate Solder out with a concussion, the Patriots moved all-pro guard Logan Mankins to tackle and inserted undrafted rookie Jeff Kline at guard. In a 41-7 victory, the Patriots ran over the defending Super Bowl champions.

“It always starts with the head guy,” Mankins said. “He doesn’t care who’s out on the field. He expects you to do your job to the best of your ability. If you don’t, he’ll find someone else. He did a good job of finding guys that are willing to do whatever they’re asked of in their role.”

In late October, the Patriots added a defensive tackle named Sealver Siliga to their practice squad. He went undrafted in 2011 — as a junior at Utah, he made the all-Mountain West team only as honorable mention. He bounced between the practice squads of the 49ers, Broncos and Seahawks, appearing in only one game.

Sunday, he started at defensive tackle as one of Wilfork’s replacements. Along with a sack, he was part of stopping Ray Rice on a fourth and one that all but sealed the victory.

“Bill is a great leader of men,” linebacker Rob Ninkovich said. “He gets us all in the right place, all in the right schemes, everything that benefits us as individual players.”

The Patriots changed their offense on the fly, relying on two sawed-off wide receivers. Julian Edelman, 5 feet 10, played quarterback at Kent State in college and was picked 232nd overall in 2009. As a free agent this summer, he agreed to return to New England on a one-year contract with a base salary of less than $1 million. He has caught 96 passes for 991 yards. Brady calls him “Minitron.”

Danny Amendola, the Patriots’ 5-11 replacement for Welker, has bounced in and out of the lineup with injuries but is still second on the team in catches and receiving yards.

“What can you say? We have great leadership in Coach Belichick,” special teams ace Matthew Slater said. “He’s been able to prepare us and keep us focused. Tom, obviously, has shown great leadership and poise throughout the adversity we’ve faced this season.”

Running back Shane Vereen suffered a broken wrist and missed Weeks 2 through 9. The Patriots could have subsisted with Stevan Ridley, a bruiser who scored 12 touchdowns last year, but he fumbled his way onto the bench and, for one week, the inactive list. Their top running back Sunday was LeGarrette Blount, whom they acquired last year for little-used wideout Jeff Demps and a seventh-round pick.

“Whatever happens,” Blount said, “we’re going to adapt to it.”

In the Patriots’ locker room Sunday, a reporter wanted to know if Blount considered himself the team’s No. 1 back. As Blount demurred, Vereen crouched behind him and grumbled.

“Asking about our [expletive] role,” Vereen said. “That’s not how this group operates.”

The Patriots’ gaudy record could be viewed with skepticism. They have won just four games by more than a touchdown and have outgained opponents by just 13 yards per game. Without three unlikely comebacks, they would be scrounging for a playoff spot. The close calls may portend another early playoff exit — the Patriots have three postseason wins in the past five years. Then again, during their 41-7 throttling of Baltimore’s champions, they again played like a powerhouse.

“You know what, coming in, on the bus ride in here, I felt great,” Ninkovich said afterward. “I knew that we were going to beat these guys. Some hand gestures coming from the fans, it’s always a good motivating thing. Again, I was confident. I knew that we worked hard. We had put in the work, and that’s what it’s all about.”

On the Friday before the Patriots pasted the Ravens, Belichick took his team to the movies. They watched “Lone Survivor,” the Mark Wahlberg movie about a Navy SEAL mission in Afghanistan.

“I didn’t feel like they needed anything — just changed up the routine a little bit,” Belichick said. “I think the movie certainly had the messages of leadership, perseverance, preparation, and then execution. It’s one thing to prepare; it’s another to actually go out there and play the game and go through the battle that they did. So, that was a great message, no question. And a great movie.”

Sometimes, even through his dull monotone, Belichick can make the blandest NFL clichés seem vividly real. He still has Brady behind center, and he doesn’t care about who is on injured reserve. He cares only that the machine rolls on.