Just Win, Baby. Then win again.

The idea in all sports is to build off a playoff season. That message has been lost on the Falcons, Texans, Vikings and Redskins, also-rans all. Even the Super Bowl champion Ravens are under .500.

There are some very bad teams in the NFL this year — Tampa Bay and Jacksonville have legitimate shots at going 0-16. And down at the bottom of the standings, although hardly in the abyss the Bucs and Jaguars have fallen into, are three 2012 division winners: Atlanta, Houston and Washington. Plus, NFC wild-card qualifier Minnesota.

What’s gone wrong? Plenty.

Injuries can be blamed in part, but not primarily because all four teams stumbled and bumbled even with most of their regulars on hand. Now, with the likes of Julio Jones, Brian Cushing and Harrison Smith on the sidelines, there are some built-in excuses for such failures.

Hogwash.

“We haven’t been consistent in anything we’ve done in seven games,” said Falcons coach Mike Smith, whose team’s plunge to 2-5 is the most astounding. “That’s the entire football team, the entire coaching staff, and we all take responsibility for it.”

The Falcons barely missed making the Super Bowl last season, and they seemed to address their few concerns with the additions of running back Steven Jackson and rookie cornerback Desmond Trufant. But they barely can see New Orleans atop the division, and also trail Carolina as they struggle to run the ball with Jackson hurt, and their defense fails to make big plays.

A revival seems out of the question with games against the Saints, Packers and 49ers ahead and an 0-3 road mark.

Same thing for the Texans, who can’t afford a loss Sunday night when they host AFC South leader Indianapolis. Houston already is three games in arrears, is down to third-string quarterback Case Keenum and, despite having a solid defense led by last year’s top defensive player, J.J. Watt, has made few big plays during a five-game slide.

Indeed, Houston (2-5) has only five takeaways, and with the offense so charitable with the ball (16 turnovers), that makes for a minus-11 differential.

Can’t win like that.

With two games remaining against the Colts, plus New England and Denver ahead, a third straight playoff berth might already be gone.

“Nobody can feel sorry for themselves,” coach Gary Kubiak said this week after the team “went out and practiced in a flood … and had good energy, pushing through, trying to get better as a football team. That’s what I expect them to do.”

Improvement on their 2012 turnaround was what everyone in the nation’s capital, and many people elsewhere, expected from the Redskins. Instead, there has been serious regression, particularly on defense, which wasn’t all that staunch last season.

Most disappointing has been Washington’s inability to get out of the gate, outscored 67-20 in first quarters. The Redskins (2-5) aren’t much on closing either, outscored by 18 points in the final period.

“We just have to execute better from the get-go,” said quarterback Robert Griffin III, who only now is getting back to full fitness after offseason knee surgery that made him less maneuverable early this season. “We work on stuff all week in practice and we have to be able to translate that over to game day, and that takes everybody. We just can’t have some of the things that we’ve been having: missed assignments, missed throws, dropped passes. All those kind of things can lead to not being successful and we’ve got to eliminate those.”

Minnesota’s slide is less surprising because the Vikings (1-6) had some elements of being a flash-in-the-pan playoff qualifier a year ago. They rode one of the great performances in NFL history, Adrian Peterson’s MVP season with 2,097 yards rushing. But with their offensive line underachieving and their quarterbacks struggling, Peterson has become just another very good back at the mercy of his surrounding talent.

The Vikings’ defense, which had 44 sacks last season, has only 14 so far. There’s no continuity anywhere, which doesn’t bode well for coach Leslie Frazier and his staff.

“We’re trying to create a mindset that has to come from within because it’s not like it’s the beginning of a new regime,” Frazier said, “and we have a bunch of veterans on our team that are familiar with how we do things. So you really have to approach them at where they are and try and present to them where we are as a team, and what has to change. And then they have to buy into some of the things you are talking about that need to change and accept that, and that’s the only way that I know that you can create change with the familiarity that we all have with one another.”

In this case, familiarity has bred collapse.