In the NFL’s first game this season, the New England Patriots lost at home by 15 points. The Patriots defense gave up 42 points and 537 yards. Tom Brady was sacked three times.

Clearly, the Patriots’ dynastic romp through the NFL was over. Right? It’s what everyone was saying the next morning.

That was when we should have known that the 2017 NFL regular season would defy convention. But did it?

The Patriots were 13-2 after their opening night flop. They have the home-field advantage throughout the AFC half of the playoffs. They are chugging along with boundless ease.

But outside of New England’s ceaseless ascendancy, this indeed has been an NFL season that defied convention.

As proof, let’s go back to the first week of the 2017 schedule.

The Atlanta Falcons pulled out a narrow road victory. Aaron Rodgers led the Green Bay Packers to a hard-fought win. The Dallas Cowboys and the Denver Broncos won authoritatively at home.

Those outcomes neatly aligned with preseason expectations. But they turned out to be mirages.

The Falcons, though they crept into the playoffs, revealed themselves as fragile and erratic. Rodgers’ broken collarbone demonstrated how quarterback-centric the NFL has become, as the Packers collapsed without him. The Cowboys, distracted and weakened by the Ezekiel Elliott suspension saga, stumbled aimlessly until they were no longer relevant. The Broncos went from feared to pitied, squandering a promising 3-1 start with eight consecutive defeats.

But elsewhere during the opening week, the results held prescient revelations.

The Jacksonville Jaguars had 10 sacks in a romp. The Los Angeles Rams won by 37 points. The Philadelphia Eagles forced four turnovers in a resounding defeat of the Washington Redskins. The Carolina Panthers defense gave up just 3 points and won easily. The Buffalo Bills prevailed in a trap game, soundly dispatching the New York Jets.

Every one of those winners advanced to the playoffs.

True, the New Orleans Saints did not precisely fit the pattern. They lost in the first week of the season, but they put up a good fight in Minnesota, where only one road team won this season. The Saints have since won 11 of 15 games.

And let’s talk a little about pro football’s postseason tournament, which begins this week. The most noticeable thing about the playoff bracket? The teams that are not in it.

No Packers, Cowboys, Seattle Seahawks, Detroit Lions or New York Giants — all of them playoff teams a year ago. The shift of power this season is stark: Eight of the 12 teams in the postseason did not make the playoffs a year ago. Buffalo had not reached the postseason since 1999. In fact, four of the NFL’s six longest playoff droughts ended this season when you include the Rams (2004), the Jaguars (2007) and the Tennessee Titans (2008).

It is undoubtedly refreshing to have some new blood involved in an NFL January, but be forewarned. Especially in the NFC, the newcomers at the top have little in the way of recent playoff track records.

How do you pick a favorite between the top two NFC seeds when Philadelphia’s last playoff victory was in 2008?

Since the Eagles have the NFC home-field advantage through the postseason, you could say the road to the Super Bowl goes through Philadelphia, but only if you are naive. Just when the Eagles had definitively established themselves as a rising power, a torn knee ligament ended the season of their transformative quarterback, Carson Wentz.

Alas, on the AFC side, there is no worrisome history clouding the minds of the regal and reigning kings of the NFL. New England has won its last six home playoff games and is 17-3 in home postseason games during this century.

The Pittsburgh Steelers might have the verve and experience to thwart the Patriots, but from an entertainment standpoint, the ideal matchup for the conference title game would have the upstart Jacksonville tramping into New England’s Gillette Stadium.

The Jaguars have considerable problems on offense, but their defense is formidable. They are also among the league leaders in sacks. And no one is more aware of how a relentless pass rush can unnerve Tom Brady than Tom Coughlin, the former Giants coach and the driving force behind Jacksonville’s revival.

Coughlin’s crafting of the Giants’ two Super Bowl upsets against the Patriots may seem like ancient history, but it is still fresh in his mind.

If the Jaguars get to Gillette this month, Coughlin will be standing at a white board in the days before the game to help concoct a plan that can derail the Patriots’ Super Bowl train.

That ending would have a ring of familiarity, and still certify this season as a defiance of convention.