The Toughest Divisions in the NFL (Part 1)


Outside of working through my list of twenty things to do before training camp, I have been attempting to rank NFL divisions by difficulty.  You often hear owners, managers, coaches, and fans use the excuse of “playing in a tough division” for a bad season.  This carries some weight, but there are still ten games played outside of a team’s division and not every division can be the toughest.

Without further ado, I’ll explain my methodology and break down the top four divisions in the NFL.  (I’ll do five through eight, next time.)  This might be a little bit mathematically thick, but nothing too complicated. To start, I calculated the standard deviation of wins for the entire NFL.  This came out to 3.27 which indicated a fairly normal distribution around the obvious average of 8 wins per season.   I then used each team’s 2011 record to calculate how many deviations they were from the mean.  Teams that were 8-8 were right on the mean and therefore 0 deviations away, while the biggest deviations went to Green Bay, Indianapolis, St. Louis, New England and San Francisco.  I then did some math to indicate whether teams were to the right of the mean (indicating a winning record) or to the left (a losing record) and ranked teams by conference and then ranked the entire league.

Next, I looked at opponent’s records and win percentage (OWP).  This is often used as a predictive (forward looking) indicator which I think is completely useless.  There is so much offseason movement and general parity in the NFL that using the prior season’s record of your current season’s opponents is next to meaningless.  In other words, strength of schedule rankings are a joke; however, using OWP to look backwards and analyze the previous season is much more useful and meaningful.  A team that had an easy “strength of schedule” initially could have had a nightmare schedule when all was said and done.

Finally, I used these numbers to create a weighted composite score which allowed me to assign rankings. I used individual team scores to get an average rank for the division. The rank score was weighted 70% for rank of standard deviation.  25% of that 70% was each team’s rank in the entire NFL since 25% of a team’s schedule is cross-conference with the other 52.5% being the standard deviation rank in each team’s home conference.  The final 30% of the composite score was the record of each team’s 2011 opponents.

I admit there are many other factors which can play roles in how tough a team is and therefore how good a division is.  Factors such as key injuries, home-away scheduling, distance travelled, etc. can all play a role.  That being said, I do think that this break down can offer some interesting insights.

According to my calculations, here are the top four divisions in the NFL.

1. The AFC North with an “average composite rank” (ACR) of 8. This should come as little surprise since the AFC North sent three teams to the playoffs last season, all three with an above .500 record.  This boosted their standard deviation score.  The AFC North also had the best average ranking of OWP (9), with Baltimore having the fourth most difficult schedule overall, and Cleveland the third.  The combined OWP for the AFC North in 2011 was .513, tying it with the AFC West for second in the NFL.

2. The NFC East comes in second with a 2011 ACR of 12.  I have to admit that I was surprised at this.  One of things that started me on this project was listening to an obnoxious Cowboys fan explain why the self-declared “America’s Team” perennially underperforms.  The NFC East is home to two of the most meddlesome owners in the NFL (Jones and Snyder) and I enjoy seeing their teams routinely fail.  All that being said, the NFC East is also home the 2011 Super Bowl champion New York Football Giants, who had the toughest schedule last season, facing an OWP of .547.  The NFC East had the highest OWP (.514), just beating out the AFC North and West.

The NFC East came in second due to unimpressive overall team records.  The division winning Giants had a 9-7 record, with Philly and Dallas at 8-8, and lowly Washington at 5-7.  This put their division deviation at -0.61 with an average conference rank of 9, and NFL rank of 16.

3.  In third place is the AFC West.  The AFC West had three teams with records of 8-8. The only outsider was Kansas City at 7-9.  The AFC West actually had the same difficulty of schedule as the AFC North, but a much worse overall division record of 31-33, compared to the North’s 31-27.  The division deviation was -0.31, with the Kansas City Chiefs being the only reason it dropped below zero.  They had a division OWP of .513 with Denver facing the second hardest schedule in the NFL with an OWP of .543.  I don’t mean to give the AFC West short shrift, but it essentially got third place by being completely unremarkable which still managed to make it better than five other NFL divisions.

4. Fourth place goes to the NFC West.   The NFC West actually tied in ACR with the AFC West with 13, but had slightly worse deviation and OWP with two teams hovering at or near .500 (Arizona and Seattle, respectively) and one runaway team, the 49ers. The Rams came in with the second worst record in the NFL but the fifth hardest schedule.

The NFC West had the same total deviation as the NFC East with -0.61, but as a division, faced a slightly easier schedule with a combined OWP of .507.  San Francisco actually had only the 24th hardest 2011 schedule by OWP and was the only NFC West team with overall sub-.500 competition. That pushed their individual composite rank to 17, last in the division.  Arizona had the highest with a composite rank of 8.  Overall, the NFC West was helped by a total deviation close to zero and generally high OWP ranks of 5 (Rams), 8 (Cardinals), and 13 (Seahawks).

A quick final note:  I know that people are going to argue and disagree with my results.  I am far from a professional mathematician and admit this is only amateur level analysis.  However, any good analyst, no matter what level they are, tells the story that the data provides and doesn’t make the data fit the story they want.  I started out with the intention of disproving the idea that the NFC East was a tough division.  I was wrong.  Manipulating the data to make my desired conclusion true would have made me dishonest and unworthy of being read by you.

I have no doubt people will be surprised to not see the NFC North or AFC East in the top half, but that’s just the way the results came out based on my analysis.  As you will see when I post the bottom four divisions, having one great team doesn’t make a division great.  As can be seen with the NFC East and AFC West, parity within a division is a much better indicator of difficulty.

All of my raw data and calculations are up on Google docs and and can be found by using this link.  I hope this was at least minimally enlightening and, if you’re a numbers and Excel geek like me, enjoyable.