The AFC playoff contingent this year is harder to read than Bill Belichick’s game face. Did he just beat the Colts for the AFC title, or did he just lose his top receiver to a catastrophic knee injury?

Damned if we know, at least not this year.

In fact, it’s an incredibly unusual postseason in both conferences, but especially here in the AFC. The top seeds are riddled with statistical bullet holes despite their lofty records — the Chargers are the worst rushing team in football, the Colts can’t stop anybody on the ground.

The wild cards, meanwhile, carry into the postseason some of most impressive statistical credentials: The Ravens have been stout top to bottom in many of the Quality Stats we use to measure teams at Cold, Hard Football Facts; while the shutdown pass defense of the Jets is the single scariest unit of any team in the AFC tournament.

One thing I do know: Whoever makes it through the AFC this year should be favored to win the Super Bowl. The AFC went 37-27 in interconference play this season and hasn’t lost the interconference battle since 1995. The NFC, meanwhile, has enjoyed just three Super Bowl victories since 1997.

So here’s how we size up each AFC contender, with their average ranking in the seven key Quality Stats we use at Cold, Hard Football Facts.com and with our take on their various strengths and weaknesses when seen through these indicators of success.

Baltimore — Fear the Raven
Average ranking in CHFF’s Quality Stats: 6.7

The Ravens are the true dark horse in the AFC race. They’re just 9-7 and enter the postseason with the No. 6 seed. But they’re statistically stout — so stout, in fact, that you wonder why their record is so humble.

The answer is that, like the Patriots, the Ravens have shown an inability to close games this year. It began with their six-point loss to the Patriots on Oct. 4 (they were one late dropped pass away from perhaps tying the game) and continued with a three-point loss to Cincinnati, a two-point loss to Minnesota, a two-point loss to Indy and a three-point loss two weeks ago at Pittsburgh.

In other words, Baltimore is a couple of plays away from being looked at as the scariest team in the AFC. More importantly, the Ravens are the AFC’s best playoff team based upon our Quality Stats. The Ravens rank in the top 10 in six of our seven indicators, all but Passing Yards Per Attempt (where they’re No. 13). They’re also No. 1 against the run (3.43 YPA) and boast the third-best defense in football (16.3 PPG).

The Ravens are capable of beating anybody, yet their record indicates that they let too many opportunities slip out of their fingers this year.

Don’t forget, though, that the Ravens battled for the right to go to the Super Bowl last year, while the NFL produced a 9-7 conference champ in 2009, too (Arizona).

Bottom line: Do not underestimate the Ravens.

New England — Haunted by the ghosts of playoffs past
Average ranking in CHFF’s Quality Stats: 9.9

All of the pigskin “punditry,” including the Cold, Hard Football Facts, have had difficulty gauging the real Patriots this year. But that unknown quality about them makes them a very interesting team here in the playoffs — they could win it all or they could get bounced Sunday. (Yes, going out on a limb is a CHFF specialty.)

Statistically, the Patriots dominate in no one area, but they have no true weaknesses, either — just mediocre areas in which they’re serviceable. It adds up to a team that’s as solid — on paper anyway — as any team in football.

The weakest link on the Patriots is a defensive front that ranks No. 18 on our Defensive Hog Index — that’s not a good sign when you consider that indicator is the single best predictor of postseason success in sports.

The Defensive Hog Index is 20-2 picking playoff winners since we introduced it in 2007, and the No. 1 team in the indicator has won the Super Bowl both years (2007 Giants, 2008 Steelers). What Patriots fan can forget the Giants D-line manhandling the league’s best offense in Super Bowl XLII?

(The Packers, for the record, are No. 1 on the DHI this year.)

But keep another thing in mind: The big AFC powers this year, San Diego and Indy, field some of the worst Defensive Hogs in football (more on that below).

Offensively, the Patriots still pass the ball as well as anybody, and I don’t understand the freak-out over the Wes Welker injury. New England fans — we have to keep reminding you — watched this team win three Super Bowls with the worst collection of second-rate castoff wideouts to ever hoist multiple Lombardis. And yet these same fans seem curiously attached to the wideouts who have never won anything.

But I digress.

New England’s biggest problem is psychological: Peyton Manning spooked Bill Belichick and the Patriots defense in the 2006 AFC title game with 32 second-half points in the greatest conference-championship collapse in history.

The Patriots have never recovered mentally. We saw a bit more of that spookiness last week when the team surrendered 21 fourth-quarter points to Houston — sure, a lot of backups were in. But it was not a good sign.

Bottom line: If the Patriots go down this year, it won’t be because Tom Brady and the offense were hamstrung by the Wes Welker injury. It will be because the defense fails them when they need it most. In fact, fourth-quarter defensive failure is now this organization’s calling card.

Indianapolis — A rusty, vulnerable victory wagon
Average ranking in CHFF’s Quality Stats: 10.0

The Colts are very, very good in many areas. But they are dominant in none. The 14-2 Colts won in 2009 on guts and guile, much like the 14-2 Patriots of 2003. But there are three critical chinks in the Indy armor:

1. The Colts will have gone an entire month without playing to win — since Dec. 17 — when they step on the field for the divisional playoffs Jan. 16 or 17. 

2. Their Defensive Hogs are a complete disaster. We chronicled the super-human success of the Defensive Hog Index above (Patriots section). And in this area, the Colts rank 30th, ahead of only the dreadful Lions and Rams. They can’t stop the run, they don’t force quarterbacks into mistakes and they don’t get off the field on third down. Sooner or later, these weaknesses will cost them.

3. For all their unmatched regular-season success, including a single-decade record of 115 wins from 2000 to 2009, the Colts might be the worst big-game team in history. They’re 128-48 (.727) in the regular season since 1999 but just 7-8 (.467) in the postseason.

When measured across the board in the key Quality Stats we use at Cold, Hard Football Facts, the Colts actually rank behind Baltimore and just the tiniest shade behind New England.

In their best indicator of success, Passing Yards Per Attempt, they rank fourth, behind the Chargers, Saints and Texans, the last a team that’s sitting at home eating bon-bons right now.

Bottom line: The Colts won’t blow out anybody in this postseason, much like they didn’t blow out any decent teams in the regular season. This is a gutty but very vulnerable team that will have gone an entire month without fighting for a victory when it next steps on the field.

San Diego — Let the buyer beware
Average ranking in CHFF’s Quality Stats: 10.9

I was shocked when finally looking under the statistical hood of the San Diego victory machine this week. The numbers simply do not add up to an 11-game win streak and a 13-3 record.

The Chargers pass the ball better than any team in football (7.96 Passing Yards Per Attempt) and they’re a highly efficient offense — No. 2 in an indicator we call “Scoreability.”

But they’re a very mediocre pass defense — No. 17 in Defensive Passer Rating. That’s not a good sign when you consider that the closest thing to an elite quarterback they faced this year was Tony Romo (an impressive 20-17 win for San Diego in Dallas). So a Manning or Brady will probably find great success moving the ball against the Chargers.

Perhaps more importantly, the Chargers are a dreadful 26th on our all-important Defensive Hog Index: They don’t stop the run (4.45 YPA, 24th); they don’t pressure the quarterback (22nd in Negative Pass Plays) and they don’t get off the field on third downs — opponents convert 40.4 percent of opportunities (23rd). Those pathetic numbers put San Diego in a dead heat with Tampa’s Defensive Hogs.

San Diego is also dead last running the ball (3.33 YPA), a Cold, Hard Football Fact you can use as a cudgel to beat over the head any friends who still cling to the quaint “establish the run” theory of pro football.

Yet the Chargers are the “it” team in football right now with a 13-3 record and a league-leading 11-game win streak. But I’m not sold: The streak includes seven wins over the Chiefs, Raiders, Giants, Broncos, Browns and Redskins. That’s hardly Murderer’s Row.

Philip Rivers and friends did beat the Eagles at home and the Cowboys by three on the road. Good wins. But not great wins. As noted above, the NFC was clearly inferior to the AFC this year. In fact, not a single team in the powerful NFC East had a winning record this year against the weak AFC West. So, there ya go.

Bottom line: The Chargers are the NFL’s “hot” team, but also a team that’s very, very beatable against the right opponent — an opponent with an elite quarterback, for example. And there are two elite quarterbacks in the AFC playoffs.

New York — A one-trick pony (but a scary one-trick pony)
Average ranking in CHFF’s Quality Stats: 11.6

The turnaround that rookie coach Rex Ryan inspired with the Jets this year is truly phenomenal. We chronicled all the numbers this week at Cold, Hard Football Facts and at SportsIllustrated.com.

The bottom line is that the Jets field the best defense in football this year (as you knew). But more importantly, they absolutely field the No. 1 pass defense in football: They boast as 58.8 Defensive Passer Rating, a truly stout unit in this day and age and about 25 points below the league average; they field the shutdown corner du jour in Darrelle Revis; and they surrendered just eight TD passes all year.

In addition, they’re the NFL’s best defense on third down: Opponents succeeded on just 31.5 percent of attempts.
It all adds up to a team that has the one antidote it needs in a playoff tournament littered with Pro Bowl quarterbacks in Brady, Manning and Rivers.

I like New York’s chances to beat the Bengals starters this week, after manhandling the no-show Bengals 37-0 last week.

But after that, it gets tricky:

The struggles of rookie quarterback Mark Sanchez (12 TD, 23 INT, 63.0 passer rating) have been well chronicled, though he has gone without a single pick in three of the last four games, all wins. (Conversely, he had one three-pick game against the Falcons in December and it proved to be New York’s only loss in the final six games.)

The Jets run the ball extremely well, too: 172.2 YPG (first) and 4.53 YPA (sixth). But running the ball well doesn’t matter if you can’t also pass it well. So it all comes down to the play of Sanchez. If he makes mistakes, the Jets cannot win against the field in front of them. If he doesn’t make mistakes, their defense gives them a shot to take down any team on the board.

Once the Jets get past the Bengals, I actually like their odds in Indy. The Jets run the ball extraordinarily well and the Colts, as noted above, are extraordinarily bad stopping the run. The Colts rely on their passing attack to win, and the Jets field the best pass defense in football. And remember, the Colts enjoyed just a narrow 15-10 third-quarter lead in that tussle against the Jets two weeks ago when they decided to pack it in for the season.

Bottom line: I would not be surprised by a Jets-Chargers or Jets-Patriots AFC title game.

Cincinnati — Thanks for visiting, please come again
Average ranking in CHFF’s Quality Stats: 14.3

Cincinnati is a mediocre team that gutted its way into the playoffs thanks to an amazing four wins over divisional rivals Pittsburgh and Baltimore in the first nine games of the year.

The Bengals deserve all the credit in the world for those victories, but they’ve more or less bumbled along the jungle floor in the weeks since, losing to Oakland, failing to put away the dreadful Lions at home (23-13), getting smoked at Minnesota (30-10), edging out a bad Chiefs team at home (17-10) and then turning in last week’s no-show performance against the Jets (37-0 loss). Cincy did, however, go toe-to-toe with the Chargers (27-24 loss) back on Dec. 20.

That’s not a confidence-building stretch of football for the Bengals. The Cold, Hard Football Facts Quality Stats do not inspire confidence, either: Cincy is no better than an average team, with an average ranking of 14.3 in our seven key Quality Stats. The Bengals rank in the top 10 in only one indicator, Defensive Passer Rating, which gives them a chance to at least slow down the likes of a Rivers, Manning or Brady.

But this is a very, very mediocre passing team (almost perfectly mediocre statistically). And despite its reputation as a run-first club this year, the Bengals average just 4.07 YPA on the ground (24th). Even the Patriots are better than that (4.12 YPA).

Bottom line: Don’t be shocked by Cincy’s first-round loss to the Jets. For this organization, just making the playoffs is a victory.

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The Cold, Hard Football Facts AFC pick: The Chargers top the Jets in the conference title game and face the Packers in Super Bowl XLIV.