Recently, Football Outsiders posted an article pondering the Worst Division Ever. The actual article (on ESPN's site) uses non-division records and combined net points; no attempt is made to put the divisions in order.
APR already gives a way to compute a power index for individual teams. This can easily be extended. Division power can be computed by averaging teams power index on a per-division basis.
By computing the division powers at the end of each season, APR provides a numerical ordering of divisions, much like the weekly team power rankings.
Some Disclaimers
I only have score data going back to the 1960 season, so the ranking of those 1930's divisions will languish in obscurity.
It should also be noted there's been a lot of changes in the NFL since 1960: the merger of the AFL and NFL, the introduction of a number of new teams, the introduction of sudden-death overtime for regular season games, playoff seeding, the salary cap and free agency, the division realignment in 2002, and rule changes too numerous to mention.
Comparison of division (or team) power indexes from year to year (or between the AFL and NFL prior to the merger) should not be taken too seriously.
APR's Worst Divisions, 1960-2008 (week 11)
Of course, I'm not going to let any of that stop me. Here is the top 20+ worst divisions since 1960, including the 2008 season up to week 11. Obviously (right?) the end-of-season rankings for the 2008 divisions are subject to change.
Here are the 20 worst (and a few more) divisions in the data set, ordered from worst to... not worst. Hopefully the table is pretty self explanatory; divisions marked with a '*' were mentioned in the linked article.
| Rank | Year | Division | Power | |
| 1 | 1969 | NFL Century | 1.1406 | * |
| 2 | 2007 | NFC West | 1.1542 | |
| 3 | 2004 | NFC West | 1.1544 | * |
| 4 | 1991 | AFC East | 1.1565 | |
| 5 | 2008 | NFC West | 1.1565 | * |
| 6 | 1965 | NFL East | 1.1594 | |
| 7 | 1979 | NFC Central | 1.1662 | |
| 8 | 1982 | NFC West | 1.1700 | |
| 9 | 2008 | AFC West | 1.1760 | * |
| 10 | 1982 | AFC Central | 1.1765 | |
| 11 | 1976 | NFC West | 1.1770 | |
| 12 | 1998 | AFC Central | 1.1789 | |
| 13 | 1975 | NFC West | 1.1790 | |
| 14 | 1984 | AFC East | 1.1800 | |
| 15 | 1985 | AFC Central | 1.1813 | |
| 16 | 1961 | AFL West | 1.1821 | |
| 17 | 2002 | NFC North | 1.1826 | * |
| 18 | 1976 | AFC East | 1.1847 | |
| 19 | 2007 | NFC South | 1.1848 | |
| 20 | 1967 | AFL East | 1.1866 | * |
Other divisions mentioned: | ||||
| 27 | 1969 | AFL East | 1.2023 | * |
| 73 | 1968 | AFL East | 1.2342 | * |
| 76 | 1979 | NFC West | 1.2367 | * |
| 109 | 1984 | AFC Central | 1.2528 | * |
| 111 | 2008 | NFC North | 1.2541 | * |
By APR's measure, the 1969 NFL Century is the worst of the lot by a pretty significant margin. The 2007 NFC West doesn't look that bad from the Fooball Outsider's metric (non-division record was 14-26 (35%) with a combined net points of -213; marginally better than those mentioned). But both the Rams and 49ers had miserable seasons in 2007 (very much like 2008, so far) that are (perhaps) not completely reflected in their records or net points.
APR's Best Divisions, 1960-2008 (week 11)
Of course, the same data set yields the best divisions, too. Here are the top 10 divisions, ranked from the best, descending.
| Rank | Year | Division | Power | Playoff Notes |
| 1 | 1965 | NFL West | 1.4513 | Packers won NFL Championship |
| 2 | 2004 | AFC East | 1.4441 | Patriots won Super Bowl XXIX |
| 3 | 2007 | NFC East | 1.4356 | Giants won Super Bowl XLII |
| 4 | 2006 | AFC East | 1.4154 | Patriots lost AFC CG |
| 5 | 2006 | AFC South | 1.4104 | Colts won Superbowl XLI |
| 6 | 1978 | AFC Central | 1.3953 | Steelers won Superbowl XIII |
| 7 | 1979 | AFC West | 1.3919 | Chargers, Broncos 1-and-done |
| 8 | 1979 | AFC Central | 1.3916 | Steelers won Superbowl XIV |
| 9 | 1970 | NFC Central | 1.3896 | Vikings, Lions 1-and-done |
| 10 | 1992 | NFC East | 1.3865 | Cowboys won Super Bowl XXVII |
The highest-ranked 2008 divisions are the NFC East (currently ranked #20), and the AFC South (currently ranked #34). I have another post coming that looks at the correlation of division power and Super Bowl winners. Stay tuned!
