A weird statistical anomaly through seven weeks of the NFL season: The top four defenses, in terms of yards allowed, are all from the same division.
The AFC North has thrown down the gauntlet so far, with Baltimore (272.7 yards per game), Cincinnati (278.5), Pittsburgh (279) and Cleveland (291) ranking 1-2-3-4 right now. As you might expect, the AFC North is also tied for the least combined losses among its four teams at nine -- the NFC North, thanks to the unbeaten Packers, share that mark.
Baltimore also leads the league in points allowed per game at 13.8, with the remainder of the division in the top 10 as well.
Is it a coincidence? Maybe. A result of drawing the mediocre NFC West in crossover games? That probably helps.
But this is nothing new for the Ravens and Steelers. Pittsburgh has led the league in yards allowed four times in the past 10 years and hasn't finished outside the top 10 since 1999. The Steel Curtain has lived up to its name in points allowed, too, finishing with a No. 1 ranking in that category last season.
It's a similar story for the Steelers' arch-rivals. Baltimore had the NFL's top defense in 2006 and finished third in points allowed each of the past three seasons.
The AFC North's defensive domination may not be so much an oddity, then, as it is Cincinnati and Cleveland closing the gap.
The Bengals and Browns are following similar models right now: Building around a young quarterback on offense and relying on a stingy defense to help ease the learning curve. Andy Dalton has stepped up in his rookie season in Cincinnati, while Colt McCoy has held on to his starting job in Cleveland.
You could even make the case that we're witnessing a changing of the guard in the AFC North. The Steelers and Ravens are both getting up in years on defense -- several of Pittsburgh's key pieces, like Troy Polamalu and James Harrison, have endured injuries recently; Baltimore still relies heavily on the aging Ray Lewis, Terrell Suggs and Ed Reed.
That's not to say either defense or franchise suddenly will fall off the table in the near future, but the window may be closing just a tad.
And if there's a benefit to finishing in third or fourth place most years, it's that the result is often a high draft pick. Cleveland used its top two picks in both 2010 and '11 on defensive players already in the starting lineup -- Joe Haden and T.J. Ward last year; Phil Taylor and Jabaal Sheard this year.
A lot of NFL teams have taken steps toward opening the playbook and winning shootouts, Patriots-style, but the AFC North has held its ground. Pittsburgh's prolific passing game is the closest thing to a run-and-shoot in the division at the moment, and it's far short of the up-tempo styles we see in places like Green Bay, New Orleans and New England. Baltimore and Pittsburgh laid the blueprint for succeeding in the AFC North and beyond, and those plans started with defense. Finally, Cincinnati and Cleveland may be catching on.