I thought it would be fun to look at the SRS ratings for each division in the AFC since realignment in 2002. SRS, of course, stands for Simple Rating System: at its core, it’s just points differential (per game) adjusted for strength of schedule. To derive division ratings, I simply took the average of the SRS ratings of each of the four teams in any given season.

Let’s start with the best division in the conference over the last 14 years, the AFC East. From 2002 to 2015, the average AFC East team season has produced an SRS of +2.0. That’s the best division in football, and by a pretty large margin, too (second is the AFC North at +0.9). That said, the AFC East is on a bit of a decline lately: the division was below-average in 2012 and 2013, and barely above-average last year. But in ’04, ’06, ’09, and ’10, the AFC East produced some outstanding seasons. Take a look:

The division hasn’t exactly had a lot of turnover at the top: the Patriots won the division every year but ’02 (Jets) and ’08 (Dolphins), and New England obviously is the driving force here. The Patriots are at +9.5, while the other three teams average a -0.6 rating. But the AFC East also doesn’t have a bottom-feeder, and that helps. The AFC doesn’t have a Raiders, Jaguars, or Browns dragging it down; the Bills SRS rating since ’02 is -1.4, which is easily the best of any 4th-place team in any division in the NFL. Having the best team in the NFL and the best worst team makes it pretty easy to see why the AFC East fares so well here.

What about the AFC North? The division has been choppier than you might expect: the Bengals had some down years before they were good, and the Browns are an anchor on the division’s rating:

Things are only trending up slightly for the division — at least on paper — but that may be misleading. The Steelers are strong Super Bowl contenders, the Bengals have won double digit games in four straight seasons, and the Ravens should rebound from a disaster 2015 campaign. Had Baltimore been healthier last year, it’s likely that the 2015 AFC North would have been the division’s best effort yet: even with a terrible Browns team, there’s a good chance 2016 can take that title.

The AFC South used to be good, I swear. In fact, I have proof:

From ’06 to ’08, this division was really good. In 2007, the AFC South sent three teams to the playoffs! But the trend is really clear: the division has decreased significantly over the last decade, with 2015 actually setting a new low. In fact, the 2015 AFC South’s average team SRS rating of -6.4 was the worst for any division other than the NFC West since 2002. That caveat is kind of important: the NFC West had *five* seasons from ’04 to ’10 that were worse than last year’s AFC South.

How about the AFC West? It’s been pretty up-and-down: the ’07 to ’12 period was a definite nadir, but the division was really strong in the surrounding seasons. In some ways, you could say the Chiefs are the straw that stirs the AFC West cocktail: how Kansas City goes, the division goes. The correlation coefficient between the Chiefs’ SRS rating and the AFC West’s SRS rating was a whopping 0.89, the highest of any AFC team.

Thought of another way, the Chargers are driving in the wrong direction: when San Diego is good, the rest of the AFC West is bad; when the Chargers are bad, the rest of the AFC West is good. San Diego’s SRS rating had a 0.11 correlation with the AFC West’s average rating over this time period, which is pretty crazy since the Chargers’ rating makes up 25% of the AFC West’s rating.

Finally, let’s put all four divisions on one graph.

I’m not sure what the takeaway from this graph is, other than the AFC South has been the worst division in the conference four years running. But then again, the AFC West was the worst division in SIX straight seasons from ’06 to ’11, with ’08 and ’09 being really bad years.

What stands out to you?