The Jets are eliminated from playoff contention, their season has been a major disappointment, and their fans are tuning them out to the tune of tens of thousands of empty seats at home games.

And yet they could be three days away from the second-biggest win in the 48-year history of the franchise.

All they have to do is go to Foxboro, Mass., and beat the undefeated New England Patriots, a team that is already being mentioned as one of the greatest in the history of the sport, a team that beat the Jets by 24 points to open the season, and a team that will be motivated to win by a much larger margin given the fallout of that game, when the Patriots were caught illegally filming the Jets’ coaches and were disciplined by the league as a result.

It’s both the greatness of the Patriots and the surrounding circumstances — in which the Patriots spying scandal increased the already obvious personal animosity between Jets coach Eric Mangini and his mentor, Patriots coach Bill Belichick — that mean that if the Jets could somehow manage to win, it would be the biggest victory for the franchise outside Super Bowl III.

The other games that might be considered the second-greatest in franchise history include beating the Colts 41–0 at the start of the 2002 playoffs; the Monday Night Miracle in 2000, when the Jets beat the Dolphins in overtime after trailing 37–7 in the fourth quarter; reaching the AFC championship game by beating the Jaguars 34–24 in the 1998 postseason, and beating the Raiders in the American Football League title game in 1968 to advance to Super Bowl III.

But none of those wins will be replayed in NFL Films clips for generations the way a Jets upset of the Patriots on Sunday would — at least, if the Patriots really are the great team everyone thinks they are. An otherwise perfect Patriots season is a requirement for a Jets win over the Patriots Sunday to be remembered as an upset for the ages.

Perfection is exactly what most fans have come to expect from the Patriots. So unbeatable are the Patriots, in the eyes of the public, that the point spread for Sunday’s game opened at between 25 and 27 points in favor of the Patriots. Richard Gardner, the manager of the online sports book Bodog, said this point spread is the highest any NFL game has had in more than 30 years, although the spread is shrinking slightly, as most of the early money has gone on the Jets, with the points.

But what makes a potential upset so alluring for Jets fans isn’t the magnitude of the point spread. It’s the rivalry between the franchises, which goes far beyond the fact that they both play in the AFC East. It’s Belichick spurning the Jets before taking the Patriots job, and it’s Mangini spurning Belichick to leave his staff in New England to coach the Jets. And it’s the relationship between the two coaches, which went from frosty last season to radioactive this season when Belichick’s staffer got caught cheating on the Jets’ sideline.

In fact, Belichick and Mangini might have the most acrimonious relationship two NFL coaches have ever had. It’s not unusual for assistants to become head coaches and have ill will toward their old bosses, from Buddy Ryan and Mike Ditka to Belichick and Bill Parcells. But with Belichick and Mangini, it’s so personal that there’s even speculation that the coaches will decline to shake hands after Sunday’s game. (For the record, NFL spokesman Greg Aiello said yesterday that there are no league rules requiring postgame handshakes. “It’s up to the coaches,” Aiello said.)

This has been a tremendously disappointing season for Mangini, who a year ago looked like the bright young star of NFL coaching and this year looks overmatched and unprepared for the job. Ending Belichick’s run at a perfect season would be the only way to paint 2007 as anything other than a complete failure. Both Belichick and Mangini like to say they prepare for every game the same way, but deep down, Mangini must consider this game more important than last week’s game against the Cleveland Browns, or next week’s game against the Tennessee Titans.

So could the Jets really win Sunday and earn their second-biggest victory ever? It seems silly even to think about it. The Patriots are blowing their opponents out by more than three touchdowns a game, and they’ll be focused and motivated against the Jets. A massacre is a lot more likely than an upset.

Then again, no one gave the Jets a chance before Super Bowl III.

Mr. Smith is a writer for FootballOutsiders.com.