It’s the gray that matters in Week 17

Between the whiteouts in Seattle and Foxborough, and the victory blackout in Detroit, there are still plenty of NFL gray areas.

Are the San Diego Chargers on the verge of an unbelievable comeback?

Are the Denver Broncos, New York Jets and Arizona Cardinals falling apart before our very eyes?

Seventeen observations, arguments and random thoughts heading into Week 17:

1 One of the best moments of the 2007 season was when the Giants played New England tough in an ostensibly meaningless finale, almost denying the Patriots their 16-0 finish. Considering the Giants wound up hoisting the Lombardi Trophy, maybe some other playoff-bound teams will take their lead in Week 17 and think twice about resting their starters.

2 Green Bay is definitely pulling for the Jets this weekend. If New York winds up making the playoffs, the draft pick the Packers got in the Brett Favre deal goes from a third-rounder to a second-rounder. It started as a fourth, but Favre logged enough playing time to bump it up to a third.

3 The greatest thing about the RCA Dome, which the folks in Indianapolis just imploded, was the city’s Habitrail-like system of tunnels allowed you to walk from your hotel to a Colts game without setting foot outside. Perfect for bitter-cold days.

4 If the Chargers beat Denver on Sunday, they will play host to a first-round game against Indianapolis. That would cause some heartburn for the Colts, considering they have lost three of four to San Diego, including a divisional game last season. If the Broncos win, however, the Colts would travel to Denver -- a much better scenario for Indianapolis.

5 Peyton Manning’s near-perfect performance in last Thursday’s victory at Jacksonville is further proof that the Colts quarterback is the NFL’s most valuable player.

6 It would be a great story for the Chargers if they were able to overcome Denver’s three-game division lead in the final three weeks of the season, but the bigger story would be the epic collapse of the Broncos. It’s hard to imagine Mike Shanahan keeping his job were that to happen.

7 Either San Diego or Denver is going to make the playoffs with an 8-8 record, whereas the Patriots could go 11-5 and be done. Something’s wrong with that picture.

8 Why, with two minutes remaining in the first half and the Broncos leading, 13-3, did Denver try a 54-yard field goal -- it ended up being well short -- instead of trying to pin Buffalo deep with a punt? That set up a short-field touchdown for the Bills and changed the game.

9 In the last four weeks, Favre has one touchdown and six interceptions. Arizona’s Kurt Warner played so poorly in Foxborough, Mass., on Sunday, he was benched in favor of Matt Leinart. Ladies and gentlemen, your Pro Bowl quarterbacks.

10 NBC’s Tiki Barber, who during his playing days was often critical of Tom Coughlin, recently requested a sit-down interview with his old coach for the network’s “Football Night in America.” But Coughlin said no. Now that’s a Tiki torching.

11 Something tells me that we’re going to see that shot Sunday of Tennessee’s LenDale White stomping on that Terrible Towel, grinding it into the mud, over and over until either the Titans or Steelers are eliminated from the playoffs.

12 There are rumors swirling around Cleveland -- a report at least one Browns player has confirmed -- that defensive lineman Shaun Smith punched quarterback Brady Quinn in the face during a recent altercation in the weight room between the teammates. Good luck with your next team, Shaun.

13 With their head-spinning turnarounds this season, the Miami Dolphins and Atlanta Falcons have raised the bar for every administration that still clings to the notion it takes three seasons to breathe life into a sagging franchise.

14 Tony Romo of the Dallas Cowboys won’t be an elite quarterback until he proves he can be a closer. In December and January games, he’s 6-9 as a starter with 16 touchdowns, 19 interceptions and one very memorable botched hold on a field goal.

15 Many people say they just knew Atlanta rookie Matt Ryan would be an outstanding quarterback right away. That’s easy to claim now. But coach-turned-analyst Brian Billick, for one, really did say that. He started singing Ryan’s praises long before the season began.

16 Wasn’t it just a moment ago that Carolina was in prime position to grab home-field advantage? Now, if the Panthers lose to the Saints, and Atlanta beats St. Louis -- which will happen -- the Falcons would win the NFC South. That would leave Carolina with the No. 5 seeding, meaning the Panthers would have to travel to Arizona for a first-round game.

17 The Chargers were flying home and roughly over New Orleans when they learned via an ESPN crawl that Denver had lost and their season was very much alive. Wonder if those cheers in the plane were loud enough to hear on the ground?

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sam.farmer@latimes.com

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(BEGIN TEXT OF INFOBOX)

Sunday’s key matchups

AFC WEST

Denver at San Diego, 5:15 p.m., Ch. 4

The winner takes the division title.

AFC EAST

Miami at N.Y. Jets, 1:15 p.m.

If the Dolphins win, they win the division title. The Jets need to win and have New England lose at Buffalo to clinch the title. The Patriots need to win and have the Jets win.

NFC WILD CARD

Dallas at Philadelphia, 1:15 p.m.

If Dallas wins, it’s in. If the Eagles win and Tampa Bay loses, and Minnesota or Chicago loses, the Eagles make it.

Other key games

NFC SOUTH

St. Louis at Atlanta, 10 a.m.

Carolina at New Orleans, 10 a.m.

Atlanta and Carolina are in the playoffs and each can still win the division title. The Falcons need to win and have the Panthers lose to win the division.

NFC NORTH

N.Y. Giants at Minnesota, 10 a.m.

Chicago at Houston, 10 a.m.

The Vikings clinch the division title with a win and a Chicago loss, and the Bears need the opposite to happen.

-- ASSOCIATED PRESS