Part II of our injury series: Do some injuries become more common later in the NFL season? And has the NFL succeeded in cutting down on concussions?
25 Aug 2014
by Scott Kacsmar
Last week on ESPN Insider we laid out the case for the 2013 NFC West being the strongest division since realignment in 2002, and with some improvements across the board the 2014 version could be even stronger. Since that article was first proposed, we have watched the 49ers lose 34-0 to Denver in the first (preseason) game ever at Levi's Stadium. Then two important players, Darnell Dockett and Sam Bradford, both suffered season-ending ACL injuries. At least the Seahawks haven't let us down yet.
No division won more often (30-10 record) or outscored opponents by a bigger margin (9.0 points per game) than the 2013 NFC West. That alone is a solid argument for being the best, but wasn't the NFC West just recently the worst division in the NFL for a long time? Yes, and by a good margin. So a dozen years into this eight-division format, we decided to collect data on just how good or bad divisions are each year. That's 96 divisions total. The method was to only focus on non-division regular-season games and combine the stats equally for the four teams (40 games per season). So unless noted otherwise, all of the following stats are from non-division games only. It's not the most complete assessment of how good each team was, but I think if you're just trying to measure the division's strength, then there's no sense in factoring in what the teams did to beat each other up.
Obviously since this is Football Outsiders we can do more than recite team records and scoreboard totals. We can adjust by opponent and situation by looking at average DVOA in these games, and the 2013 NFC West finished second there. Can you guess which division had the highest average DVOA? Hint: it was a very unbalanced year for the NFL's two conferences and this division had the best defensive DVOA since 2002. We'll get to the answer later, but try a guess now.
Technically there would be ties in the rankings here, but we broke those ties by best scoring differential. A total of 20 divisions have won at least 60 percent of their non-division games.
|Best & Worst Division Records in Non-Division Games (2002-2013)|
|1||2013||NFC West||30-10||0.750||77||2002||NFC West||17-23||0.425|
|2||2007||AFC South||30-10||0.750||78||2006||NFC West||17-23||0.425|
|3||2008||NFC South||28-12||0.700||79||2002||AFC North||16-23-1||0.413|
|4||2007||NFC East||28-12||0.700||80||2007||AFC East||16-24||0.400|
|5||2008||NFC East||26-13-1||0.663||81||2005||NFC West||16-24||0.400|
|6||2008||AFC East||26-14||0.650||82||2013||NFC East||16-24||0.400|
|7||2008||AFC South||26-14||0.650||83||2005||AFC East||16-24||0.400|
|8||2009||AFC South||26-14||0.650||84||2007||NFC South||15-25||0.375|
|9||2002||NFC South||25-14-1||0.638||85||2011||AFC South||14-26||0.350|
|10||2004||AFC East||25-15||0.625||86||2012||AFC West||14-26||0.350|
|11||2013||AFC West||25-15||0.625||87||2007||AFC West||14-26||0.350|
|12||2011||AFC North||25-15||0.625||88||2007||NFC West||14-26||0.350|
|13||2005||AFC West||24-16||0.600||89||2008||NFC North||13-27||0.325|
|14||2002||AFC West||24-16||0.600||90||2002||NFC North||13-27||0.325|
|15||2011||NFC North||24-16||0.600||91||2004||NFC West||13-27||0.325|
|16||2005||NFC East||24-16||0.600||92||2010||NFC West||13-27||0.325|
|18||2010||AFC East||24-16||0.600||93||2009||NFC West||12-28||0.300|
|18||2003||AFC East||24-16||0.600||94||2013||AFC South||12-28||0.300|
|19||2004||AFC North||24-16||0.600||95||2008||AFC West||11-29||0.275|
|20||2010||NFC South||24-16||0.600||96||2008||NFC West||10-30||0.250|
Bet you didn't expect the 2007 AFC South to be first with a 30-10 record. The AFC South gets a bad reputation now, but there was a time when this division usually produced solid teams, beyond just Indianapolis. The 2007 season was arguably the second-best year ever for Jacksonville behind 1999's "If You're Not the Titans, We'll Beat You" campaign. The Colts helped the 2007 AFC South get three playoff teams by resting starters in Week 17 against Tennessee, but keep in mind the Titans actually had the No. 1 defense in DVOA for the full season.
It's interesting how six of the top seven divisions were all in 2007-08. Naturally, five of the bottom 10 divisions come from those two years as well. We also start to see some of the past stench from the NFC West with four of the bottom six records.
That's quite the five-year journey for the NFC West to bookmark this table from 10-30 in 2008 to 30-10 last year. Let's recall that low point. The 2008 49ers weren't bad as long as Shaun Hill (that's my quarterback) was starting, but J.T. O'Sullivan was a mess in Mike Martz's offense. This was also Mike Holmgren's final season as a head coach, and 2008 ended Seattle's streak of five consecutive playoff appearances. St. Louis finished 2-14 in the middle of a 6-42 stretch from 2007-09. The saving grace was Arizona, which somehow still emerged from this rotten division to come within 60 seconds of winning Super Bowl XLIII.
Next we'll look at the top 20 and bottom 20 divisions for scoring differential (PD).
|Best & Worst Division Scoring Differentials in Non-Division Games (2002-2013)|
|1||2013||NFC West||30-10||0.750||1072||713||359||77||2005||NFC West||16-24||0.400||789||939||-150|
|2||2007||AFC South||30-10||0.750||967||673||294||78||2011||AFC South||14-26||0.350||753||915||-162|
|3||2004||AFC East||25-15||0.625||959||678||281||79||2013||NFC East||16-24||0.400||991||1157||-166|
|4||2008||NFC South||28-12||0.700||1080||821||259||80||2005||AFC East||16-24||0.400||716||885||-169|
|5||2013||AFC West||25-15||0.625||1115||866||249||81||2012||AFC West||14-26||0.350||832||1007||-175|
|6||2002||NFC South||25-14-1||0.638||967||729||238||82||2009||AFC West||18-22||0.450||755||931||-176|
|7||2005||AFC West||24-16||0.600||1018||790||228||83||2007||NFC South||15-25||0.375||753||933||-180|
|8||2002||AFC West||24-16||0.600||1085||857||228||84||2007||AFC West||14-26||0.350||760||945||-185|
|9||2008||NFC East||26-13-1||0.663||984||758||226||85||2002||NFC West||17-23||0.425||732||938||-206|
|10||2007||NFC East||28-12||0.700||1001||789||212||86||2006||NFC West||17-23||0.425||798||1007||-209|
|11||2011||NFC North||24-16||0.600||1110||919||191||87||2007||NFC West||14-26||0.350||749||962||-213|
|12||2008||AFC East||26-14||0.650||996||824||172||88||2002||NFC North||13-27||0.325||757||982||-225|
|13||2012||NFC North||23-17||0.575||1059||898||161||89||2011||AFC West||19-21||0.475||820||1072||-252|
|14||2009||AFC East||20-20||0.500||893||737||156||90||2008||AFC West||11-29||0.275||791||1051||-260|
|15||2011||AFC North||25-15||0.625||808||666||142||91||2009||NFC West||12-28||0.300||724||996||-272|
|16||2011||AFC East||21-19||0.525||987||848||139||92||2012||AFC South||19-21||0.475||809||1084||-275|
|17||2004||AFC West||22-18||0.550||1030||894||136||93||2004||NFC West||13-27||0.325||705||1011||-306|
|18||2012||NFC West||23-17||0.575||913||778||135||94||2013||AFC South||12-28||0.300||786||1104||-318|
|19||2006||AFC East||23-17||0.575||873||738||135||95||2010||NFC West||13-27||0.325||746||1068||-322|
|20||2008||AFC South||26-14||0.650||891||764||127||96||2008||NFC West||10-30||0.250||724||1096||-372|
The 2013 NFC West again knocked the 2007 AFC South from the top with a strong group of defenses. Last year's AFC West and its three playoff teams lit up the scoreboard to help secure a top-five ranking here. In 2014 the NFC West and AFC West will meet, so that's definitely going to have a big impact on this upcoming season. Last season, both West divisions played the AFC South, which has been smashed in these rankings with the third-worst record (12-28) and third-worst scoring differential (minus-318 points). At least we know the schedule had a lot to do with that performance.
The league's two West divisions make up 65 percent of the bottom 20, but it's the NFC West bringing up the rear with four of the bottom six and the 2008 NFC West again taking the last spot. Even that year's NFC champion Cardinals had some awful losses: 56-35 to the Jets, 48-20 in Philadelphia, 35-14 at home against Minnesota, and 47-7 in New England in the snow with Matt Cassel at quarterback. At least those were solid opponents, which is why we should look at DVOA.
Before we reveal the overall DVOA rankings, the following table shows the top and bottom divisions by offensive DVOA and defensive DVOA.
|Best & Worst DVOA - Offense & Defense (2002-2013)|
|Rk||Year||Division||OFF DVOA||Rk||Year||Division||DEF DVOA|
|1||2005||AFC West||22.6%||1||2004||AFC East||-16.6%|
|2||2002||AFC West||19.6%||2||2012||NFC West||-15.0%|
|3||2004||AFC West||18.8%||3||2004||AFC North||-14.0%|
|4||2006||NFC East||13.7%||4||2008||AFC North||-13.9%|
|5||2003||AFC West||12.6%||5||2009||AFC East||-13.6%|
|6||2011||NFC South||10.6%||6||2002||NFC South||-12.4%|
|7||2013||AFC West||10.4%||7||2013||NFC West||-10.7%|
|8||2008||AFC South||10.0%||8||2007||NFC East||-9.7%|
|9||2008||NFC East||10.0%||9||2010||AFC North||-8.8%|
|10||2007||AFC South||9.1%||10||2008||NFC East||-8.4%|
|Rk||Year||Division||OFF DVOA||Rk||Year||Division||DEF DVOA|
|87||2011||NFC West||-11.4%||87||2006||NFC West||7.9%|
|88||2007||NFC West||-11.8%||88||2002||NFC North||8.1%|
|89||2012||AFC South||-12.4%||89||2013||AFC South||8.3%|
|90||2008||AFC North||-12.4%||90||2004||NFC West||8.4%|
|91||2005||NFC West||-13.2%||91||2011||NFC South||8.4%|
|92||2009||NFC West||-13.3%||92||2004||NFC North||8.4%|
|93||2004||NFC West||-14.6%||93||2003||AFC West||9.4%|
|94||2008||NFC West||-15.4%||94||2008||NFC West||10.9%|
|95||2005||NFC North||-17.9%||95||2008||AFC West||11.0%|
|96||2010||NFC West||-19.1%||96||2013||NFC North||12.5%|
Only the 2008 NFC East appears in the top 10 for offense and defense. Did you expect the 2002-05 AFC West to have a monopoly on great offense? That included the last great Oakland team with Rich Gannon's MVP year in 2002. The Chiefs had a fantastic offense all four years, but never found a defense to support, let alone match. Denver was usually very efficient under Mike Shanahan, and his job of turning around Jake Plummer might be the most noteworthy thing he did in the 21st century. The Chargers were on the way up with LaDainian Tomlinson, Drew Brees and Antonio Gates emerging as stars. That was a fun division, but mainly for fans of offensive football.
The AFC West has five of the top seven offenses, but it's the only division since 2002 to not win a Super Bowl. The playoff losses have been more excruciating than most. Every Super Bowl was close at the end from 2003 to 2012, but the last two blowouts involved AFC West offensive powerhouses (2002 Raiders and 2013 Broncos) crashing and burning against arguably the two best pass defenses (2002 Buccaneers and 2013 Seahawks) of the last 12 years. Since 2003, Kansas City has gone 0-3 in the playoffs against Indianapolis despite games where it never punted (2003), picked off Peyton Manning three times (2006), and held a 28-point lead (2013). In between 35-point playoff losses, the Broncos endured the Rahim Moore-Jacoby Jones play at home. And San Diego fans know about playoff disappointment all too well. Just start with two words: Nate Kaeding.
Is there something to playing in an offensive-driven division that's not conducive to winning championships?
Teams from top 10 divisions in offensive DVOA went 8-18 (.308) in the playoffs against non-division opponents and only two reached the Super Bowl (0-2).
Teams from top 10 divisions in defensive DVOA went 28-10 (.737) in the playoffs against non-division opponents and had a 5-2 Super Bowl record.
We're not breaking any new ground by saying dominant defense tends to drive playoff success, but what if playing in a defensive division helps to breed more defensive success? The 2007 Giants were only 13th in defensive DVOA in the regular season, but turned into a great unit in the playoffs after playing in one of the best defensive divisions we've seen recently. We had Steelers and Ravens for years, but now it's about the 49ers and Seahawks in the NFC West. Would the Broncos have been better prepared for the Super Bowl if they played something closer to Seattle in the regular season instead of feasting on San Diego (three times) and Oakland? Maybe we can answer that one specifically this year thanks to the schedule.
From the above table we can also see a lot of the old NFC West's problems were on offense (seven of the bottom 10 years). It's surprising to see the 2005 NFC West offense rank 91st given Seattle's first Super Bowl year.
Last year's NFC North takes over as the worst defensive division. That could happen in a division with Aaron Rodgers, Calvin Johnson, Adrian Peterson, Brandon Marshall, Alshon Jeffery, Matt Forte, Reggie Bush, Jordy Nelson, etc. The NFC South was actually stronger defensively in 2012, but better on offense and special teams in 2013.
For those curious in special teams, the 2002 NFC South (7.8%) had the highest DVOA and the 2013 NFC East (-7.4%) had the worst DVOA. For the latter, we can pretty much lay the blame on Washington for a miserable 2013.
The following table has the top 20 divisions in average DVOA with the bottom 20 featured in the second half.
|Best & Worst Average DVOA in Non-Division Games (2002-2013)|
Did you guess the 2004 AFC East as the top division by DVOA? Even though that year was the end of Dave Wannstedt and Ricky Williams in Miami (4-12), that was the strongest that division has been since realignment. Looking at full-season DVOA, New England finished second, Buffalo was third and the Jets were fourth in a stacked AFC. The Patriots had their first dominant team under Bill Belichick and won the Super Bowl. It was an even-numbered year, so that means Chad Pennington was really good for the Jets. If not for Doug Brien missing two field goals in Pittsburgh, the Jets would have pulled off two road upsets and been in the AFC Championship against the Patriots. Then there's Buffalo (9-7), which had the league's best special teams and would have been in the playoffs if it didn't blow the Week 17 game at home against Pittsburgh's backups. After an ugly start, Buffalo had some huge wins that year, including a 38-9 beatdown of the playoff-bound Seahawks in Seattle. Against the NFC West in particular, Buffalo was 4-0 with a combined score of 154-47, a margin of victory of 26.8 points per game.
With numbers like that, now do you see why the 2004 NFC West had the worst DVOA of any division? The best in DVOA played the worst in DVOA, but obviously there's a relationship there between the numbers that no opponent adjustment can eliminate without removing the games entirely.
We also see with DVOA just how bad the NFC West has been with the bottom six divisions all belonging to that period of football from 2004 to 2010. Before the recent years of the AFC South, the NFC West had the bottom seven divisions in DVOA. It's really not that surprising when you consider how bad the 49ers were from 2003-2010, or how Arizona usually plays minus Kurt Warner's career revival, or some of the lean years in Seattle, or the brutal play the Rams have provided since 2005. Some strong coaching, a defense-heavy focus and tons of great draft picks (including a couple of quarterbacks after round one) have put this division back on top.
Here's the division summary of cumulative statistics (non-division games only) for 2002-2013:
|Division Summary in Non-Division Games, 2002-2013|
|Division||W||L||T||Pct.||PF||PA||PD||AVG DVOA||OFF DVOA||DEF DVOA||ST DVOA|
The quality of play hasn't always been pretty, but the NFC West is the only division since realignment to win a playoff game in 10 consecutive seasons. Still, the NFC West will need several great years to pull itself out of the cellar here. The AFC East has the best overall numbers, but that's mostly because the Patriots have not had any real off year in this time. I was surprised to see the NFC East finish second in key categories, because you usually think of that division being won by a team with 9-10 wins. They do beat each other up though. The AFC South has a winning record despite a negative scoring differential and below-average DVOA. That's basically saying Peyton Manning and Andrew Luck have led the Colts to a lot of wild comeback wins. We touched on the AFC West being the best offensive division, but it's not surprisingly the worst defensive division too. The best defense belongs to the AFC North thanks to the consistency of Pittsburgh and Baltimore, though it's about time for that to start changing. Nothing lasts forever in the NFL.
Just how consistent is a division's performance from year to year? We've seen good evidence here from the NFC West that a division can be pretty bad for an extended period of time. It's the same four teams every year, so while a lot can change quickly, it's hard to completely reshape a team's identity in one year. Not everyone can land Sean Payton and Drew Brees in the same offseason and set up a decade of offensive domination.
I took our division results in non-division games from 2002-2013 and ran some year-to-year correlation tests for each stat. Remember, these are for only out-of-division games.
|Year-to-year Correlation, 2002-2013|
|Special Teams DVOA||0.44|
Average total DVOA in out-of-division games has pretty solid correlation (0.64), with offense not surprisingly being more than double that of defense. It is surprising to see special teams DVOA having better correlation than defense, which is not true when we look at teams from year to year rather than whole divisions.
We observed that 65.9 percent of divisions stay within four games of their record from the previous year. The biggest gain was 13 wins by the 2007-08 NFC South. That featured a huge change in Atlanta with Bobby Petrino and the stain of Michael Vick replaced by Mike Smith and Matt Ryan. In Carolina, Jake Delhomme was injured after three games in 2007, but returned for a playoff year in 2008.
The sharpest decline also happened at this time with the 2007-08 NFC North dropping 10 wins. Green Bay went from 13-3 with Brett Favre to 6-10 in Aaron Rodgers' first year as a starter. The Lions also dropped seven wins to an unfathomable 0-16 finish.
Likewise, 65.9 percent of divisions stay within one ranking position in average DVOA. The biggest improvement was the 2011-12 NFC West going from last to first, which obviously had a lot to do with Seattle's young talent coming together in Russell Wilson's rookie year. The biggest decline was the 2004-05 AFC East dropping from first to sixth. That was arguably the weakest New England team in this span. Buffalo couldn't make things work with J.P. Losman at quarterback. The Jets lost Chad Pennington after three games and Curtis Martin followed up a rushing title with a forgettable swansong season. Only Miami -- hey, Nick Saban era! -- got better, because it had a lot of room to do so.
We touched on this earlier, but is there anything to playing in a great division and winning the Super Bowl? Obviously Seattle just did that, but what about the last 12 years in general that has seen so many unexpected Super Bowl runs? I ranked each of the eight divisions for each year in three stats based on non-division games only:
The last 12 Super Bowl-winning divisions have on average ranked 3.0 in DVOA, 2.7 in scoring differential and 2.8 in winning percentage.
The last 12 Super Bowl-losing divisions have on average ranked 4.2 in DVOA, 4.7 in scoring differential and 4.3 in winning percentage.
So the Super Bowl winner is coming from a stronger division. In fact, five of the last 12 Super Bowls were won by the division finishing first in scoring differential. All 12 winners came from a division ranking in the top five in scoring differential and DVOA. The stat that was most predictive was scoring differential. In the 12 Super Bowls, the division with the better scoring differential was 10-2 (higher DVOA was 8-4 and better winning percentage was 9-3).
Does this mean a way to predict playoff success is to identify the strength of each division in non-division games and pick the strongest? We'll certainly take a look at that before the playoffs this year. Looking at results prior to 2002 should also be beneficial. We've seen crazy splits before, and we know most of these Super Bowls swung on one big play, but there could be something to playing in a strong division that gets a team better prepared for a championship run. Of course, being a great team and boosting your division's stats has a lot to do with these rankings. The Seahawks elevated the 2013 NFC West into rarefied company.
The fact we're talking up the NFC West as a juggernaut after such a dreadful run just goes to show the cyclic nature of division strength. Rome wasn't built in a day, nor did it fall in one either.
6 comments, Last at 26 Aug 2014, 10:23am by nat