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The general perception suggests that the NFC is the superior conference this season.  That's partially based off of recency bias, as the NFC has indeed been superior to the AFC over the past few years.  The AFC owns a slight 19-17-1 edge in inter-conference games this season, but that alone is obviously far from enough to declare that the league's power balance has once again shifted.

However, it would at least appear that the once-lopsided distinction is moving back towards an equilibrium, a notion these rankings would agree with.  Nine of the top 16 teams are from the AFC, and the second-ranked NFC team would seemingly serve as an indictment of the entire conference (I won't ruin the surprise for you, but it's a team I've discussed at length before). 
Though the Broncos and Patriots receive most of the pub, the conference's strength really lies in its depth.  These rankings may have a couple cooky placements, but for the most part, the model does a good job of staying ahead of the mainstream curve. We'll examine a couple (perceived) second-level contenders from the AFC who have thus far exceeded preseason expectations by becoming borderline top 10 squads in these rankings.

January Darkhorses?

Two AFC teams have steadily risen after a rough first month.

- Widely derided as one of this year's most likely regression candidates, the Kansas City Chiefs seemed destined to fulfill that ignominious role after a blowout Week 1 home loss to the Tennessee Titans.  Integral starters Derrick Johnson and Mike DeVito suffered season-ending injuries in that defeat, while All-Pro cornerstones Jamaal Charles and Eric Berry have both missed time with nagging injuries.  For a top-heavy roster, this would seemingly be a death blow.

Nonetheless, the Chiefs have somehow emerged from the wreckage and surged to a 5-3 record, as well as an eighth-place standing in these rankings.  This isn't the only model that likes KC, as Pro-Football-Reference has them tied for third in Simple Rating System (SRS).  That Titans loss has become arguably the season's biggest outlier, as Kansas City's other two losses are one-possession road defeats to the Broncos and 49ers. 

The Chiefs' success starts with their pass defense, which ranks third by efficiency, behind only Denver and Miami.  It's utterly remarkable that Kansas City has gotten by without Johnson or (mostly) Berry.  The Chiefs also cut erstwhile top cornerback Brandon Flowers in the offseason, while 2013 starting corner Marcus Cooper has fallen totally out of the rotation.

The pass rush is obviously the catalyst behind Kansas City's strong start, as the Chiefs lead the league with a 9.7 percent sack rate.  Justin Houston is garnering Defensive POY consideration (non-J.J. Watt category), while Tamba Hali, Dontari Poe and sneaky breakout defensive end Allen Bailey join to form one of the league's best front sevens.

Additionally, Alex Smith has moved past his persistent "game manager" label to emerge as a legitimately excellent quarterback.  Many will dismiss his 67.1 percent completion percentage as the byproduct of an ultra-conservative scheme, but the peripheral numbers suggest that Smith is actually having the best season of his career:

Those aren't just inflated by Smith's career context, either.  The Chiefs quarterback ranks eighth in Expected Points Added per play (EPA/P), eighth in success rate and 10th in Win Probability Added (WPA) per game.  Half of Kansas City's opponents rank in the top 10 in pass defense efficiency, and in those games, Smith has posed seven touchdowns, one interception and a 7.66 adjusted yards per attempt average.  That number would rank 12th if extrapolated to a whole season, quite impressive considering both the level of competition and Smith's relatively barren receiving corps.

The Chiefs' long-term concern isn't Smith or the offense, which should be fine behind Charles and a steadily improving offensive line.  Remember how I just praised the front seven's pass rush?  Well, that excellence is in stark contrast to their run defense's steady decline, where Houston and Hali are not nearly as effective:

This is where they really miss Johnson, as the drop-off to the high-motor yet limited Josh Mauga has been significant.  Berry's reintegration into the lineup will help, as the big safety provides better run support than most defensive backs, but this is still an issue.  Moreover, though the defense is not as scheme-dependent as it was in 2013, it's still frightening to think what might happen if the pass rush ever dried up (or if Houston or Hali got hurt, as was the case last year) and left the secondary exposed.

The Chiefs already have wins in hand over fellow AFC wild card contenders San Diego and Miami, and two juicy games against the Raiders await in the second half.  Next Sunday's game at Buffalo, as well as Week 16 and 17 games at Pittsburgh and home against the Chargers, respectively, appear likely to determine Kansas City's playoff fate.  Either way, it appears the Chiefs are going to surpass the doomsday forecasts following their 0-2 start.

- A few weeks ago, I pinpointed the Chicago Bears as the toughest team in the league to get a read on.  Though the Bears' implosion has since clarified the picture in the Windy City, the Pittsburgh Steelers may have taken that mantle after two dominant victories.

Ben Roethlisberger is the obvious storyline, and he's been about as great as 12 touchdowns in two games would suggest.  In reality, though, the Steelers are hitting big passing plays at roughly the same rate.  Pittsburgh hit 20 plays of 25 or more yards over the first seven weeks, most in the league in that span; over the past two weeks, they have accrued seven such plays, also leading the league.  That's roughly three per game in both instances; it's just that four of those seven plays in Weeks 8 and 9 went for touchdowns.

Obviously, Big Ben's touchdown rate is not sustainable, and his EPA and success rate should sink back to his typical borderline top 10 area, which is where he sat before this incandescent fortnight.  But even before their three-game winning streak, Roethlisberger was never the Steelers' problem.  What's really relevant is how the rest of the team has changed since that three-touchdown debacle of a defeat to Cleveland.

The most obvious change is location, as all three of Pittsburgh's wins have been at Heinz Field.  We shouldn't dock the Steelers for taking care of business after a fortunate break from the schedule-makers, but the most glaring change has been in Pittsburgh's run defense.  The change is obvious on the EPA graph:

It's not just the running game either, as the Steelers have conceded 7.86 yards per play on the road, well below the NFL average of 6.73 yards per play away from home.  Nor is this difference due to a quirk in the schedule, at least when looking at opponents' run success rate.  Pittsburgh has already played both division games against Baltimore and Cleveland; their other splits consistent of the ninth and 25th-ranked rushing attacks on the road and the seventh, 23rd and 29th-ranked running games at home.  These are similar schedules that would not portend major splits.

The Steelers play four of their next five games on the road, and location is obviously out of their control.  Apart from Roethlisberger, the other major change has been turnover rate.  After accruing six turnovers in their first six games, the Steelers defense has forced seven in the last three games.  Those turnovers have also been particularly well-timed—two straight turnovers catalyzed a 24-point flurry against Houston, William Gay recorded a pick-six against Indy and Jason Worilds' interception shifted the complexion of the Baltimore game. 

That's obviously not a repeatable streak, either. The Steelers have been a weird turnover team—though they've forced a relatively plausible 33 turnovers over the past two regular seasons, Pittsburgh has also had eight games with no turnovers forced, seventh-most in the league in that span.  A lack of secondary speed makes this a streaky turnover defense, and with Roethlisberger taking his customary share of downfield shots, his current career-low 0.9 percent interception rate is likely to rise as well.

In fairness, the Steelers do have games against the Jets and Titans coming up, meaning there is a very real chance they enter their Week 12 bye at 8-3.  It would be hard to fathom them missing the postseason with that type of head start, even with a tricky final month.  But unlike the Chiefs' pass rush, the Steelers do not have an ace in the hole to hang their hat on.  Thus, even if their two-year postseason drought ends, Pittsburgh looks like a flawed team elevated by an MVP candidate at quarterback.