Marcus Spears and Desmond Howard explain why they like the idea of the NFL adding one more team from each conference to the playoff format. (1:09)

Here come the 7-seeds! NFL owners voted to expand the playoff field, which will move the league to seven playoff teams per conference, starting this season. Is that going to let several lesser teams into the postseason tournament? Based on win-loss record, of course -- most 7-seeds will be 9-7 or even 8-8.

But based on play-by-play analysis, not all of these teams will be relatively weak. On average, the 7-seed would not be as good as the sixth seed, which is usually not as good as the fifth seed. But there have been some very good teams that just missed the playoffs due to a combination of luck, schedule strength and performance in close games. Including seven playoff seeds will let some of these teams into the postseason, with hope of a Super Bowl title despite an unimpressive win-loss record.

The NFL's current structure of six playoff teams per conference began in 1990. What if the NFL had just gone straight to 7-seeds back then? We've gone all the way back to find the best would-be 7-seeds according to Football Outsiders' DVOA (defense-adjusted value over average) ratings, explained here. Note that a number of the best teams to miss the playoffs aren't even listed below. The 2004 Buffalo Bills are the only team to ever miss the playoffs with a DVOA rating above 30%, but the Bills would have only been the ninth seed because of tiebreakers. Other particularly strong teams that wouldn't have been 7-seeds include the 2002 Miami Dolphins and Kansas City Chiefs as well as the 2005 San Diego Chargers, all of whom had DVOA above 20%.

10. 2010 New York Giants (10-6), 13.0% DVOA (9th)

Eli Manning finished the 2010 season with 4,002 yards, 31 touchdowns and 25 interceptions. Chris McGrath/Getty Images

This is the Giants team that was knocked out of the playoffs by the Miracle at the Meadowlands II, when Philadelphia scored 28 points in the fourth quarter to beat the Giants 38-31 and sweep the season series. The Eagles and Giants both finished 10-6, but the Eagles won the division on that tiebreaker. Then the Giants had a three-way tiebreaker with the Buccaneers and Packers for the wild card, which the Packers won on "strength of victory." And after sneaking into the playoffs with the sixth seed, the Packers ended up winning the Super Bowl.

A seventh seed in 2010 would have put a dangerous Giants team into the playoffs over Tampa Bay based on win percentage in common games. The 2010 Giants had a very strong defense, third in DVOA, and also ranked 10th on offense. A game between the Giants and the No. 2 seed Chicago Bears would have been one of a handful of our imaginary 7-vs.-2 contests where the No. 7 seed had the higher DVOA rating. Chicago was 11-5 but ranked only 14th in total DVOA, while the Giants were ninth.

With mostly the same personnel, the Giants were not as good the following regular season, ranking 12th in DVOA due to defensive decline. But 9-7 the next year was good enough to get into the postseason, and the Giants got hot, winning the Super Bowl as a fourth seed.

9. 2008 New England Patriots (11-5), 13.1% DVOA (9th)

The Patriots still went 11-5 in 2008 with Matt Cassel filling in for Tom Brady. Rick Stewart/Getty Images

This was the year Tom Brady tore his ACL in Week 1 and was replaced by backup Matt Cassel. The Patriots still went 11-5, which is normally enough to get you into the playoffs. But they lost both the AFC East tiebreaker (to Miami) and the wild-card tiebreaker (to Baltimore) based on having a worse conference record. The Patriots are one of only two 11-5 teams to ever miss the playoffs; the other was the 1985 Denver Broncos back when there were only five playoff teams per conference.

A seventh seed in 2008 would have given the Patriots a streak of 17 years (and counting) in the postseason, from 2003 through 2019. New England would have traveled to Pittsburgh to face the 12-4 Steelers (fourth in DVOA), who went on to win the Super Bowl and had already beaten the Patriots in Foxborough, 33-10, in Week 13.

8. 2002 Denver Broncos (9-7), 15.2% DVOA (8th)

Clinton Portis rushed for 1,508 yards and 15 touchdowns in his rookie campaign of 2002. MARK LEFFINGWELL/AFP via Getty Images

This was a strange season where 12 different teams in the AFC finished between 8-8 and 11-5. With teams so tightly bunched by win-loss record, the playoff seeds didn't follow the DVOA ratings at all. The top two teams in DVOA were the two teams in the Super Bowl, Tampa Bay and Oakland. Behind them, four teams in the DVOA top eight were AFC teams that didn't make the playoffs: Miami (3), Kansas City (4), New England (7), and Denver (8). Denver would have been the seventh seed through a complicated process where New England eliminated Miami via division record but Denver had a head-to-head win over the Patriots. (The Chiefs, with the best DVOA ever for an 8-8 team, weren't even in the discussion.)

In the first round, the Broncos would have faced the 10-6 Tennessee Titans, who were a little behind them at No. 11 in DVOA. Instead, the Titans got a bye week and then slipped past Pittsburgh 34-31 in overtime before losing the AFC Championship to Oakland. Meanwhile, Denver moved on from quarterback Brian Griese after missing the playoffs for the second straight season; the Broncos were back in the playoffs the next year with Jake Plummer at quarterback.

7. 2010 San Diego Chargers (9-7), 15.4% DVOA (8th)

The 2010 Chargers were great on offense and defense. Special teams was another matter. Joe Robbins/Getty Images

The Chargers had stars such as Philip Rivers, Antonio Gates and Eric Weddle. They had made the playoffs the previous four seasons. They led the NFL in yards per play on offense and finished second in yards per play allowed on defense. So how on earth did San Diego go just 9-7 and miss the playoffs in 2010?

The answer: a special-teams disaster. San Diego's minus-10.2% DVOA on special teams in 2010 is the fourth-worst ever measured by Football Outsiders. Just to give a few examples: In Week 1, the Chargers outgained the Chiefs on offense by nearly 200 yards but the Chiefs had 160 yards on punt returns, including a touchdown. In Week 5, the Raiders won by eight points when they got nine points off two blocked punts: one for a safety, one for a touchdown. (For the season, the Chargers had five total punts blocked.) In Week 7, the Chargers lost to New England by three when Kris Brown honked a 50-yard field goal try after a Louis Vasquez false start.

It didn't help that the AFC had two wild cards that were better by both win-loss record and DVOA: Baltimore (12-4, fifth in DVOA) and the New York Jets (11-5, sixth in DVOA). But in our imaginary world of 7-seeds, the Chargers would have made the playoffs despite their special-teams failures, traveling to No. 2 seed Pittsburgh (12-4, second in DVOA) in the first round.

6. 1999 Kansas City Chiefs (9-7), 17.6% DVOA (4th)

Tony Gonzalez had 11 touchdowns in the 1999 season. DAVE KAUP/AFP via Getty Images

The 1999 Chiefs ranked in the top 10 in DVOA on both offense and defense, but they fell out of the playoffs by losing their final two games. First, they lost to Seattle in Week 16. That gave the Seahawks a sweep of the series and thus a tiebreaker for the AFC West title after both teams finished 9-7. Then the Chiefs lost in overtime to Oakland in Week 17. A win would have given them a playoff spot over Miami; instead, the Chiefs lost a tiebreaker based on common opponents.

Kansas City had a slightly higher DVOA than the team that eventually represented the AFC in the Super Bowl, Tennessee (which ranked fifth). And the team Kansas City would have played in the first round, Indianapolis, was instead upset in the divisional round by the Titans. Indianapolis was way down at 17th in DVOA in 1999 despite a 13-3 record, so the Chiefs would have had a good chance against them in the first round, although the Colts did beat Kansas City during the regular season.

5. 2017 Baltimore Ravens (9-7), 18.6% DVOA (7th)

Joe Flacco's 2017 campaign was like many of his others. Ezra Shaw/Getty Images

The last full season of the Joe Flacco era in Baltimore brought us a Joe Flacco Ravens team like all the other Joe Flacco Ravens teams: very good defense (third in DVOA), great special teams (first), and mediocre offense (21st). Despite the league's second-easiest schedule that year, the Ravens could only manage to go 9-7 thanks to a 2-5 record in one-score games.

Football Outsiders' playoff odds gave Baltimore a 97% chance of making the playoffs going into Week 17. They needed one of three things to happen: a win at home over Cincinnati, a Buffalo loss to Miami, or a Tennessee loss to Jacksonville. They had the Bengals stuck in fourth-and-12 with 53 seconds remaining, but Andy Dalton somehow found Tyler Boyd for a 49-yard touchdown and a 31-27 win. Tennessee and Buffalo wins gave them the two AFC wild cards in a four-way tiebreaker over the Ravens and Chargers.

Had there been 7-seeds in 2017, Buffalo fans would have been celebrating their first playoff appearance since 1999 without celebrating Dalton's help. (Yes, Buffalo's playoff drought would have lasted just as long -- in no year are they the would-have-been seventh seed.) Meanwhile, the Ravens would have traveled to No. 2 seed Pittsburgh (13-3, No. 3 in DVOA) for yet another hard-fought Ravens-Steelers clash. The Steelers swept the season series in 2017, but the second win took a last-minute field goal, 39-38. The two teams just ahead of Baltimore in DVOA, New England (sixth) and Philadelphia (fifth), ended up in the Super Bowl.

4. 2012 Chicago Bears (10-6), 20.5% DVOA (6th)

2012 was the swan-song campaign for Brian Urlacher. Hannah Foslien/Getty Images

There have been a number of excellent defenses on this list, but this was the best. The 2012 Bears not only led the league in defense by a large margin, but had one of the top 10 regular-season defensive DVOA ratings since 1985. Charles Tillman was the only All-Pro, but it was the last big year for a group of Chicago veterans that included Lance Briggs and Brian Urlacher. (Julius Peppers was here too, but he had a few years left.) The Bears started out 7-1, then went into an offensive tailspin, losing five out of the next six games without scoring more than 17 points in any of the losses. They won their final two games but lost a wild-card tiebreaker to Minnesota based on division win percentage.

If there had been a 7-seed, Chicago would have gotten a trip to San Francisco and a rematch with a 49ers team (11-4-1, fourth in DVOA) that had crushed them 32-7 back in Week 11. But while the Bears would have been clear underdogs in that game, they did have a better DVOA rating and the same regular-season record as the team that eventually beat San Francisco in the Super Bowl, the Baltimore Ravens (10-6, eighth in DVOA).

3. 2000 Pittsburgh Steelers (9-7), 22.6% DVOA (4th)

Kordell Stewart was a dynamic talent, but he couldn't get the Steelers into the playoffs in 2000. George Gojkovich/Getty Images

Pittsburgh is the king of the seventh seeds. Five different times since 1990 -- and four times in the past decade -- the imaginary seventh seed would have been the Steelers.

2000 was a notable year for the old AFC Central division. Three of the top four teams in DVOA came out of the six-team Central: Tennessee, Baltimore and Pittsburgh. But the two worst teams in the league by DVOA also came out of the Central: Cincinnati and Cleveland. Pittsburgh's overall DVOA was better than nine different teams with better win-loss records, but they were 2-4 in games decided by a field goal or less, and 9-7 wasn't enough to snag a wild card in the AFC.

It didn't help that backup quarterback Kent Graham had to start five games and completed less than 45% of his passes with just one passing touchdown. Some of that was schedule, as Pittsburgh faced the hardest offensive schedule in the league with four games against killer Tennessee and Baltimore defenses (one each started by Graham, one each started by Kordell Stewart).

Had there been a seventh seed in 2000, the Steelers would have traveled to Oakland to face a 12-4 Raiders team that was slightly behind them in DVOA (fifth). That Raiders team crushed Miami 27-0 in the divisional round and then lost the AFC Championship to Baltimore.

2. 2005 Kansas City Chiefs (10-6), 24.4% DVOA (5th)

Larry Johnson was the engine powering the Chiefs' offense in 2005. Ronald Martinez/Getty Images

The Dick Vermeil Chiefs had powerful offenses every year, but what made the 2005 edition different was that they also had an above-average defense. Not that far above average, just 14th in defensive DVOA, but certainly better than in previous seasons. The offense ranked fourth in DVOA, with another Pro Bowl campaign from Trent Green and a breakout 21-touchdown season from Larry Johnson despite starting just half the year. The Chiefs also get a DVOA boost from playing the fourth-toughest schedule of the 2005 season.

The Chiefs missed out on the playoffs because the Jaguars were second in the AFC South at 12-4 while the Steelers were second in the AFC North at 11-5. A seventh seed would have meant a rematch with division rivals in Denver (13-3, No. 2 in DVOA). The two teams split their season series in 2005.

1. 1991 San Francisco 49ers (10-6), 26.0% DVOA (2nd)

The 1991 49ers' season was saved by Steve Bono, though they fell just short of the playoffs. Focus on Sport/Getty Images

From 1983 through 1998, the San Francisco 49ers had double-digit wins every single year. They had a playoff appearance every year except one: 1991. A seventh seed would have changed that and given the 49ers a 16-year postseason run.

A seventh seed would have also made for a great story, because the 49ers played themselves back into contention with a third-string quarterback. Joe Montana was already out for the year due to the elbow injury he suffered in the 1990 NFC Championship Game. The 49ers started the season just 4-4 with Steve Young at quarterback. Then Young went down with a knee injury in a Week 10 loss to Atlanta. In came third-stringer Steve Bono. The 49ers lost that game by three points when Atlanta's backup quarterback Billy Joe Tolliver hit Michael Haynes for a 44-yard Hail Mary touchdown with nine seconds left. They went out the next week and lost to New Orleans by just a touchdown. At that point, the 49ers were 4-6 even though all six losses had come by less than a touchdown.

And then, Bono and the 49ers started winning, taking the last six games in a row. Bono started five of those wins, playing well enough that he finished the season third in passing DVOA behind Young and Mark Rypien. Bono went down with his own injury in Week 16, and Young came back to finish the season off with a 52-21 dismantling of the Bears on Monday Night Football.

The only problem with that big win? The 49ers had already lost the sixth seed the week before, when New Orleans and Atlanta both won to assure themselves of finishing 10-6 or better. New Orleans ended up the NFC West champion, at 11-5. And remember that close loss to Atlanta with the last-minute touchdown? San Francisco had also lost to Atlanta earlier on two fourth-quarter field goals. And with those two wins over San Francisco, Atlanta snagged the sixth playoff seed via tiebreaker.

If they had made the playoffs via seventh seed, the 49ers' playoff pedigree might very well have made them favorites on the road against second seed Detroit, which ranked only 17th in DVOA despite a 12-4 record. San Francisco outscored opponents by nearly 10 points per game during the regular season; Detroit outscored opponents by just three points per game. The Lions beat Dallas 38-6 in the divisional round, then were stomped 41-10 by Washington in the NFC Championship Game.

Thanks to Nick Korte for research used in this piece.