One of the biggest false dichotomies in sports is that teams must “build for today” or “build for the future”. The truth is that well-run franchises do both simultaneously. That’s how the Patriots can be good for over a decade despite turning over their entire (non-Brady) roster. (Well, that and they play in a perennially weak division.)
After posting this, I started wondering: Is that final, parenthetical observation really true? Has the AFC East really been weaker than other divisions? And is this really a non-trivial factor in the Patriots’ success? When I wrote it, I was basing it entirely off of hearsay; I have heard NFL commentators make this claim before, but I had never seen any sort of actual data on the subject — no in depth analyses, no nothing.
So, since basing things on hearsay is generally something I try to avoid, I went through and did the leg work. Starting from 2002 — the first year of the current divisional structure and (roughly) the start of the Tom Brady Era in New England* — and ending at 2014, last year, I recorded each NFL team’s overall record, divisional record, and non-divisional record. From this data, I derived a few simple metrics to measure the strength/weakness of a team’s division and to determine the extent to which this helped/hurt them overall.
My findings are encapsulated in the table below. For the sake of brevity, I only present the top six teams (by overall winning percentage) in each conference. These would be the “playoff” teams if the last 13 years were one giant season.
For each team, we give the team’s overall winning percentage from 2002 to 2014 (TOT WIN), their winning percentage against divisional opponents (DIV WIN), and their winning percentage against non-divisional opponents (NON DIV WIN). We also give their divisional opponents non-divisional winning percentage (DOND WIN). This tells us how good Team A’s divisional opponents were without biasing the data by including games against Team A or against each other. For example, the DOND WIN for the Patriots is .467, meaning from 2002 to 2014, the Jets, Dolphins, and Bills combined for a winning percentage of .467 against teams outside of the AFC East. In the last column of the table (DIV DELTA), we give the delta (difference) between the number of games a team would have won if they played only divisional opponents and the number of games a team would have won if they played only non-divisional opponents.** For example, the DIV DELTA for the Patriots is 0.4, meaning they would have won four-tenths more games per season had they played only the AFC East, compared to if they never played the AFC East.
|AFC Teams||TOT WIN||DIV WIN||NON DIV WIN||DOND WIN||DIV DELTA|
|NFC Teams||TOT WIN||DIV WIN||NON DIV WIN||DOND WIN||DIV DELTA|
Three things jump out at me from this table: 1) Most the good teams of the last 13 years benefited from having below-average division-mates; 2) The Patriots did not substantially benefit from playing in a weak division; 3) But the Seahawks sure did!
1) It makes sense that most the good teams benefit from being in a weak division — in part, that’s why they are good. After all, if we are just measuring “goodness” by overall record (which we are, in this case), then the teams that get six games a year against below-average opponents are going to be better than those that do not have this advantage. Also, if we think of the league as having x good teams in a given year, and these teams are assigned to divisions at random, then being good reduces your odds of being in a division with another good team, because there are only x – 1 good teams left; your pool of possible good opponents excludes you. Notice that, in fact, there are only four teams in the table that had above-average divisional opponents (Baltimore, Philadelphia, and Dallas).
2) The NFC East (minus the Patriots) was in fact weaker than an average division, but it did not really help the Patriots all that much. Overall, from 2002 to 2014, the Jets, Dolphins, and Bills did not play .500 ball outside of their division; they had a .467 mark. However, we can see that this puts the Pats in the middle of the pack among the teams in the table — nothing extreme. Furthermore, the Pats gained less than half a win a year from being in the AFC East. (They’re DIV DELTA is less than 0.5.) They were a 12-3-1 team in the division, and a 12-4 team out of it. The Patriots weren’t advantaged; they were just awesome. (And probably still are.)
3) The three teams who benefited the most from having weak division-mates are without question Green Bay, Indianapolis, and Seattle. The latter is incongruous with recent years — the NFC West has been far and away the best division the past three seasons — but it makes sense when you think back a little further. Remember, it was only five years ago that the Seahawks won the division at 7-9. Not only that, but the ‘Hawks won the NFC West each year from 2004 to 2007, and they were a Wild Card in 2003, despite being a top-5 team in the NFL (according to DVOA) once once during that space — the 2005 Super Bowl season. With seven division titles, nine playoff appearances, three conference championships, and one Super Bowl victory, you could make a strong case that the Seahawks have been the best NFC team in the newly-aligned NFL. But there is no doubting that they had a bit of help along the way — help in the form of coaches like Mike Nolan, Mike Singletary, Scott Linehan, Steve Spagnola, and Dave McGinnis.
A few other fun facts inspired by the table.
- The NFC East and AFC North have been the two top divisions since 2002. Most NFL fans probably would have guessed this. But I suspect few would have named the third best division: the NFC South.
- The Steelers are an interesting team, in that they have benefited substantially from playing in the AFC North (their DIV DELTA is 1.4, fourth largest), even though it has been a difficult division. What this means is that the Steelers raise their game against division foes — or let down against non-division foes. In fact we saw examples of both last year.
- The Seahawks were not the only beneficiaries of playing in a lousy NFC West. The Arizona Cardinals took full advantage of it, when they won the division in back-to-back years in 2008 and 2009. The 2008 NFC West was particularly dreadful. The four teams combined to win only 10 non-division games, for an ugly winning percentage of .250. None of the teams finished in the top-20 in DVOA. It was, I think it’s safe to say, the worse division in newly-aligned NFL history. And yet, their lone postseason representative came within one defensive stop of winning the Super Bowl.
- Football is weird sometimes.
*Technically it started in 2001 when there were still only six divisions in the NFL. That year three teams from the NFC East made the playoffs — New England, Miami, and New York.
**This is calculated by the formula (DIV WIN – NON DIV WIN) * 16.