The NFC South has been miserable this season: the Falcons, Saints, Panthers, and Bucs are now 6-23-1 (0.217) in games outside of the division. If Atlanta, New Orleans, Carolina, and Tampa Bay combine to go 3-7 in their ten remaining non-division games, they would eclipse the 2008 NFC West and become the worst division in modern history (at least, by record).

The NFC South has been particularly bad against the AFC North, going 1-10-1 this year. The two non-losses were the shocking upset by Tampa Bay in Pittsburgh in week 4, and the tie between the Bengals and Panthers in week 6 (which ended, you may recall, with Cincinnati kicker Mike Nugent missing a 36-yarder as time expired).

The remaining games between these two divisions in 2014 are: Cincinnati at Tampa Bay, Cleveland at Carolina, Pittsburgh vs. New Orleans, and Pittsburgh at Atlanta.  If the AFC North can go 3-1, that would up its record to 13-2-1, which would set the post-2002 mark for the best record by one division against another in a single season.

The current record? A mark of 13-3, set five times in the current era.  It was most recently done by the NFC West last year, when the only losses it had against the AFC South came versus the Colts (in the case of the 49ers and Seahawks) or the Titans (Rams).

What if the AFC North went on a clean sweep the rest of the way, finishing 14-1-1? That would be the best mark since the merger, but not the best mark of all time.  That honor belongs to the 1965 NFL West: that year, the division went 13-1 against the NFL East.  That’s going to be a tough mark to ever eclipse, as it would require a 15-1 mark given the current format. How about the best mark of the post-merger era by one division against another?

The honor belongs to the AFC West, which went 31-9 outside of its division in 1984. The division really beat up on the NFC Central, going a collective 15-2 in such games. Not surprisingly, the two losses were against the Bears (by Denver and Los Angeles).

Measuring success by one division against another across eras is complicated due to differing number of games. One tweak we can make is to use True Winning Percentage, which adds 11 games of 0.500 ball to any record. If your record is 1-0, True Winning Percentage will strongly regress that 1.000 winning percentage to the mean; if your record is 90-10, not so much: we add 5.5 wins and 5.5 loss regardless of your record. Using that methodology here would translate the AFC North’s record against the NFC South in 2014 from 10-1-1 to 15-6-2 (or 16-7), equivalent to a 0.696 winning percentage. That would be the 5th best in NFL history, and the 3rd best since the merger:

The 1991 NFC East was what TV executives apparently think that division will always be. That year, teams from the NFC East went 14-2 against the NFC Central, with both losses coming by three points (Giants at Bengals), with one going to overtime (Dallas at Houston).

A 3-1 finish would give the AFC North a 13-2-1 record, good enough for a 0.704 true winning percentage.  One more loss would knock it behind the five 13-3 teams of the post-2002 era, but so far this year, the AFC North has been dominating the NFC South at a historic level.