31 Jan 2009
by Ned Macey with sidebar by Vince Verhei
The surprising run of the Arizona Cardinals to this year's Super Bowl coming one year after the Giants' surprising championship have raised some concerns that the regular season is becoming meaningless. To me, these concerns are based on two other, slightly different concerns. One is that bad teams are advancing deeper into the playoffs. The other is that major upsets are occurring.
To see how real this "problem" is, I decided to take a quick survey of playoff results since 1995 (i.e., years where we have DVOA). This study is not comprehensive, but it seems informative and worth sharing. The currency is DVOA because, well, that's what I think the best measure of team quality is. Therefore, the Steelers' 2005 run seems much less surprising even though they were a sixth seed.
To answer the first question, I looked at simply the DVOA of teams that have advanced deeply into the playoffs. The Cardinals have the lowest DVOA of any team to make the Super Bowl since 1995. The 2007 Giants are second. So, there is something somewhat unique about the past two seasons.
Still, a closer look makes it seem less unique. The Cardinals and Giants have DVOAs of -0.5% and 0.0% respectively. The 2003 Panthers had a DVOA of 0.7%; the 2001 Patriots had a DVOA of 6.2%. These are hardly radical differences. Also, while one mediocre team has come through, the dominant Patriots eased into the Super Bowl last year, and this year's Steelers, and their 27.0% DVOA, are a worthy team. Here is a list of Super Bowl participants by DVOA since 1995:
|Super Bowl teams by regular-season DVOA
(winners in blue)
There appears to be a trend toward slightly inferior teams making the Super Bowl more often, but it is hardly earth-shattering. The eight worst teams all come from different years. More importantly, most of the weaker teams have one thing in common: fewer road games. Seven of the ten worst teams played one or fewer road games to reach the Super Bowl. They were inferior teams who, through the vagaries of seeding or other upsets, ended up with home field advantage a fair amount.
Furthermore, the 1995 playoffs saw the woeful Colts (-10.9%) make the AFC Championship game, while in 1996 Jacksonville (-0.9%) repeated that feat. In 2000, the Vikings (-2.5%) made the NFC Championship game. In 2004, the Falcons (-2.8%) made the NFC Championship.
If the Packers had won the overtime game against the Giants last year, then their run would have hardly been historic. The Eagles certainly had opportunities to beat the Cardinals this year. Considering the previous runs of 2003 Carolina and 2001 New England, the runs by the Giants and Cardinals just do not seem too unprecedented.
The second question, of course, is whether or not we have seen a rise in large upsets. Since 1995, 40 games have matched teams who were separated in DVOA by 20% or more. The better team is 28-12 in those games. Five of those 12 losses have taken place in the past two seasons. Of course, these upset-filled years are not entirely unique. Four of these games took place in 1995-1996, including three in 1995 alone.
What is notable about the five upsets in the last two seasons is that the Cardinals and Giants account for all of them. They are the two anomalies. Over the past two seasons, those two teams are 7-0, with the closest DVOA split being 8.9%. The other seven games with splits that big or larger have all been won by the "better" team.
Another factor not sufficiently discussed with regards to the Cardinals is home field advantage. Home field advantage is worth about 17% in DVOA. If we adjust for home field, then only the Giants really stand out. The Giants suddenly have four of the ten biggest upsets in this time period. The Cardinals have just one of the top 34, their road win at Carolina. Accounting for home field advantage, the Cardinals' victory over the Eagles was only slightly more surprising than the Eagles' victory over the Giants. Their win over the Falcons was actually expected.
For perspective on how the Cardinals' march has not been too surprising, consider the 2000 Ravens. Few people dispute that they were a "worthy" champion. They ranked second in overall DVOA. Of course, they went on the road to win three games, including wins at Tennessee (the best team in DVOA) and Oakland (fourth best). Like the Cardinals, the Ravens won two games that, once you adjusted for home field advantage, they should not have won.
Two upsets appears to be the magic number. Only two teams have had more than two home-field adjusted upsets in the playoffs: the 2005 Steelers and the 2007 Giants. (The Steelers' first one came after they knocked out the Bengals' best player.) Two upsets happens all the time. The 1995 Colts, 1996 Jaguars, 1997 Broncos, 1999 Titans, 2000 Ravens, 2001 Patriots, 2003 Panthers, 2005 Panthers, and 2006 Colts all had two upsets. It seems what would have been more historically anomalous is if the Eagles had beaten the Cardinals.
Of course, if the Cardinals win Sunday, then we suddenly have three years in the past four where three upsets have occurred. Given how close some of the above teams were to winning a third game -- 1995 Colts, 1999 Titans, and 2003 Panthers –- a close Cardinals win would hardly be unfathomable. If Kordell Stewart had properly been called out of bounds, Mike Jones had missed a tackle, or John Kasay had not kicked out of bounds, we may have seen three upsets more often. Plus, all three of those teams were at least 22% worse in DVOA than the team they almost beat.
The Giants obviously provide a unique story, hard to write off as a minor fluke. They faced each opponent at close to full strength. They had no Music City Miracle, Al Del Greco game, or Tuck Rule. Still, had the Packers beaten them, and they lost in overtime, then we would not be having this conversation. If Asante Samuel had caught the interception, we still might not be having this conversation.
If Arizona loses, it seems the Giants anomaly is merely skewing our perception. Upsets happen all the time in the playoffs (as they do in the regular season). Some blame could go to the new playoff format that let the Cardinals get into the playoffs, but A) the Cardinals probably could have won 10 games if they were trying, and B) the Giants last year made the playoffs with 10 wins as a Wild Card; the 2001 Patriots had a bye; the 2003 Panthers won 11 games.
Furthermore, the league had a similar run of wildness in 1995 and 1996. The Colts and Jaguars in those years respectively made surprising runs to the AFC Championship with bad teams. In 1995, Green Bay (10.5% DVOA) won at San Francisco (41.0% DVOA). In fact, adjusting for home field, three of the five biggest upsets occurred in 1995 and 1996: 1995 Colts over Chiefs, 1995 Packers over 49ers, and 1996 Jaguars over Broncos.
I feel pretty comfortable arguing that nothing radical has changed in how to value the playoffs. The Giants achieved a new level of performance in the playoffs, but one incredible run does not mean the system is "broken." Some odd seeding led to a pretty mediocre Cardinals team getting two home games, which undoubtedly helped it reach the Super Bowl. If we take the 2007 Giants and say they are an anomaly, then we can relax and enjoy playoff football, appreciating the occasional upset but knowing that it takes a very good team to win the Super Bowl.
Now, if Arizona wins by 20, pretend you never read this and wait for my article on how everything you knew about the playoffs has changed.
(Ed. Note: I liked Ned's argument against my recent complaints but wanted to point out two things. First, it wasn't really an upset for the 2004 Falcons to make it to the NFC Championship; 10 of the top 11 teams that year were AFC teams and Philadelphia was the only NFC team with a DVOA rating above 2.3%. Second, we make upsets look a little more common by only going back to 1995; we don't have DVOA yet for 1991-1994, but based on Pythagorean projection, we can say those were four fairly upset-free postseasons. -- Aaron Schatz)
About a year ago, I broke down the strengths and schedules of all 42 Super Bowl winners and determined that the 2007 Giants had completed the least likely Super Bowl run of all time. How do this year's Cardinals compare?
At the start of the playoffs, last year's Giants had a 6.9-out-of-1,000 chance of winning the Super Bowl. This year's Cardinals had an 11.3-out-of-1,000 chance. If they beat the Steelers today, they would be the second most unlikely champ of all time. Up next: The 2006 Colts (12.7), 1980 Raiders (35.1), 1976 Raiders (42.1), and 2005 Steelers (55.1).
The difference between the Giants and Cards all comes down to the Super Bowl opponent.
|NFC Champs expected win percentage|
|Year||Team||Wild Card||Div. Round||Conf. Champ||Super Bowl|
The first three games for the 2007 Giants and 2008 Cards virtually wash out. Arizona had a 4.317 percent chance of REACHING the Super Bowl, compared to the 4.334 percent chance for the Giants. Neither of these is the lowest of all time; that honor goes to the 06 Colts and their 4.137 percent chance.
That being said, judging each Super Bowl by itself, an Arizona victory would be the third biggest upset ever, behind only Giants-Pats and Jets-Colts in Super Bowl III.
Incidentally, at the start of the playoffs Pittsburgh's odds of winning the Super Bowl were 190.5 out of 1,000 (or 19.1 percent), which would rank 22nd out of 43 Super Bowl champs -- almost exactly the median. They would be the 12th least likely Super Bowl Champ to REACH the Super Bowl; they were only slight favorites over San Diego, and were actually underdogs to Baltimore.
Why have the last three years produced such unlikely champions? One reason is the four-team division format, which makes it more likely that a mediocre team will be paired with three subpar opponents and have a free playoff spot handed to them. That's clearly what happened to this year's Cards. In most other divisions, they're not a champion and probably miss the playoffs.
It's less obvious with the 2006 Colts; that team went 12-4 and won the division by four games, but that's somewhat deceiving. The Colts actually finished with a worse point differential than the 8-8 Jaguars (+67 to +97) and were a ridiculous 8-3 in one-score games. If we added a good team to the AFC South, two of those close wins may have turned into close losses, and the Colts would have been 10-6 and fighting for a Wild Card spot.
Speaking of, there are also more Wild Card teams than in prior years. In the 1970s and 1980s, with three divisions and four or five playoff teams per conference, the Cardinals and Giants don't even get in the postseason. In 1988, the sixth seed in the NFC would have been the 10-6 Giants, who had won the Super Bowl two years prior and would win it again two years later. If they get in, maybe they beat a team like San Francisco, which also went 10-6, and went on to win the Super Bowl against Cincinnati.
As I said, that's only part of it -- the six seeds have been around now for almost 20 years, and this trend only goes back three or four seasons -- but I think it's a relevant part.
For more of Vince's writing, be sure to check out his blog at vinnyv.com.
18 comments, Last at 06 Feb 2009, 5:51pm by Bjorn Nittmo