If Kansas City loses the home-field advantage for the AFC playoffs, it might not be the disaster some of its fans think. After all, the Chiefs had that edge in 1995 and 1997 and lost their first postseason game both times.

On the other hand, their 45-27 loss Sunday in Denver had negative overtones. It was a reminder of last season’s defensive failures, when the Chiefs finished 8-8 and out of the playoffs for the fifth straight season. Denver gained 508 yards, including 218 rushing and five touchdowns by Clinton Portis.

“We’ll look back on this as either a great moment or a bad moment,” said linebacker Shawn Barber, who was in Philadelphia last season and was signed to beef up Kansas City’s defense. “It will be a great moment if we use what we learned to make improvement. It will be a bad moment if we don’t.”

The Chiefs clinched their first playoff berth since Marty Schottenheimer’s team finished 13-3 six years ago but lost to Denver in their first playoff game. They will clinch the AFC West title with either a win or a Denver loss in their last three games — a virtual certainty.

But despite its gaudy 11-2 record, Kansas City hasn’t been playing well of late.

Sandwiched between its losses to the Bengals and Broncos are narrow wins over weak San Diego and Oakland. And coming up in two weeks is a trip to Minnesota, which looked rejuvenated Sunday against Seattle and has the offense to take advantage of defensive lapses.

That means the Chiefs might not even get a first-round bye — Indianapolis (10-3) is only a game behind, and New England (11-2) has only one conference loss to two for K.C.

That the Chiefs would have a first-round game seemed unthinkable as they ran off nine wins to start the season. In the AFC, that could mean a game against Denver and Portis.

“At the start of the season, if anybody had said, ‘You guys are going to be 11-2 after 13 weeks,’ I think we would have taken it,” quarterback Trent Green said after the debacle. “But the way we lost, it’s very humbling.”

Here’s an overall look at the playoff picture:

AFC

Clearly the stronger conference, where the Patriots clinched the East by beating Miami. Indianapolis leads the South by a game over Tennessee (9-4), but has beaten the Titans twice, effectively a two-game lead with three to play.

Baltimore (8-5) took a one-game lead in the North by beating (and beating up on) Cincinnati (7-6).

“We’ll be all right,” Bengals coach Marvin Lewis said after the loss, and he’s correct — two wins in three games and Cincinnati has its first winning season since 1990, a major achievement for a team that has been the league’s laughingstock for a decade.

Tennessee is a game ahead of Denver (8-5) and Miami in the wild-card race. The Dolphins also are 8-5, but the Broncos’ 7-3 conference record is two games better than Miami’s 5-5, and that’s the tiebreaker because they didn’t meet this season.

New England can get home-field advantage for the playoffs if it wins its final three games, against Jacksonville (4-9) and Buffalo (6-7) at home and the Jets (5-8) on the road.

How daunting would the Patriots be with two home playoff games?

In four home games since beating Tennessee, 38-30, Oct. 5, the Patriots have allowed only three field goals and have two straight shutouts. They won in the snow Sunday, a major consideration during Foxboro’s winters.

NFC

The Eagles (10-3) clinched a playoff spot Sunday by beating the Cowboys, 36-10, and have a two-game lead over Dallas (8-5) in the East with three games left. If they win their final three, they get home-field advantage.

Minnesota (8-5) leads Green Bay (7-6) in the North. More important, Sunday’s 34-7 win over the Seahawks was the Vikings’ first dominant game since they hit a dry spell after a 6-0 start.

“We want to win in December,” said Daunte Culpepper, who threw three touchdown passes. “We’ve just got to take this momentum into next week. I have no doubt in my mind it will carry over.”

The loss by Carolina (8-5) to Atlanta and Michael Vick in overtime was its third straight and kept it from clinching the South. But the Panthers can do that with one win in its final three games, against the Cardinals, Lions and Giants, who are a combined 11-28.

Dallas and Seattle lead for the wild-card slots. But Bill Parcells’ young Cowboys have lost three of their last four, including two straight by a combined 76-31. The Seahawks also have an upcoming game in San Francisco, which is 6-1 at home.

That means Green Bay (7-6) has a pretty good chance at a wild-card spot if it doesn’t catch the Vikings. In fact, two wins might get the Packers in. They are at San Diego and Oakland (each 3-10), then get Denver the final week at Lambeau Field, not a friendly place in late December, even for the likes of Portis.

Defending champion Tampa Bay is 6-7 and needs to win all three, including a tough closer at Tennessee, to have a shot at a wild-card spot.