Things just don't get any easier for the Seattle Seahawks. When the Russell Wilson era began in 2012, they immediately developed a built-in rivalry with the division's strongest team, the brutally dominant San Francisco 49ers. After Wilson lost his first meeting against the Niners, he threw four touchdowns in a 41-13 rout in Week 16 of his rookie season. Seattle split its 2013 regular-season contests with San Francisco before famously vanquishing the 49ers in that postseason's NFC Championship Game (the "Sorry Receiver" game). Since that loss, the Niners have gone through three head coaches while posting a 13-19 record.

At the end of the 2013 season, though, a new rival began to peek through the clouds. The Arizona Cardinals hired Bruce Arians, traded for Carson Palmer and narrowly missed out on the playoffs with a 10-6 season. That run included a rare 17-10 defeat of the Seahawks in Seattle in Week 16. The Seahawks swept a Palmer-less Cardinals team in 2014, but with Palmer recovered from a torn ACL, the Cardinals roared to the top of the NFC West in 2015. Arizona went 13-3, including a 39-32 comeback win over Seattle in the Pacific Northwest, before things went south at the very end of the year. The Cardinals were blown out by the Seahawks in Week 17, only for the NFC champion Panthers to destroy both the Seahawks and Cardinals in consecutive weeks in the postseason.

Now, as we enter 2016, the Cardinals and Seahawks rank among the favorites to win Super Bowl LI. The biggest obstacle in their way, unfortunately, is each other. The easiest path to the Super Bowl, as last year reminded us, is with home-field advantage along the way, and it's always going to be more difficult for a team like the Cardinals to finish with the conference's best record when they have to play twice against a team as good as Seattle. The Panthers were excellent last year, but they finished behind Arizona and Seattle in DVOA and faced the league's easiest schedule. The second-place team in the Panthers' division was the 8-8 Falcons. It might not surprise you to remember that the Panthers went 5-1 against the NFC South and outscored their brethren by 81 points in those games.

Seattle and Arizona have it rough. But how rough? How often do teams as good as the 2015 Cardinals and Seahawks end up in the same division? And, with the expectation that both teams will again be among the league's best in 2016, how does the presence of such talented competition nearby impact each team's respective Super Bowl chances?

History Says...

It would be great if we had an advanced metric like DVOA dating back to the beginning of time, but unfortunately, it runs back only through 1989. Our best simple measure of team performance, one that predicts future performance better than win-loss record itself, is point differential. To try to find teams and divisional races similar to the one Arizona and Seattle fought last year, I went back and ranked each team in each given year by point differential.

Russell Wilson has played eight games against the Cardinals, and the Seahawks are 5-3. He has 13 touchdown passes and four interceptions in those games. AP Photo/Ross D. Franklin

Then, I took the top two teams in each division going back to the AFL-NFL merger in 1970 and found what the average of their point-differential rankings was to get an estimate of their skill levels. Even I can admit that sentence was no fun, but it gives us a good idea of how great the teams at the top of each division were. This sort of methodology confirms that the Seahawks-Cardinals race in the NFC West last year was one of the toughest in modern league history. The Cardinals (+176) ranked second in point differential, and the Seahawks (+146) were just behind them in fourth. Their average ranking, then, was third. (For AFC North fans, the Bengals and Steelers were fifth and seventh, respectively.)

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That's just about as tough as it gets. There are 17 other times since 1970 in which the top two teams in a division have had an average point differential of three, most recently the 2013 race between these same Seahawks and 49ers. The Seahawks finished that year by winning their first Super Bowl, but they were the exception to the rule: Of those 34 teams, each among the four best in football in their respective years, five won the Super Bowl.

Five races in league history have involved even tougher competition, including three 1-2 divisional punches that included the two best teams in football by point differential. Let's run through those five races chronologically in advance of the possibility that Arizona and Seattle might join them in 2016:

1997 AFC West

Kansas City Chiefs (13-3, +143 point differential, second in league) and Denver Broncos (12-4, +185 point differential, best in league)

This was a matchup, by point differential, of the two best teams in the league. Only the Packers (+140) and arguably the 49ers (+110) were in the same ballpark as the Broncos and Chiefs; nobody else in the league had a point differential better than +80. These two teams split their season series, with the Chiefs eventually winning the division by virtue of a narrow victory over the Broncos at home when Pete Stoyanovich hit a 54-yard field goal as time expired. Ironically, the Chiefs' special teams collapsed in horrific fashion during a playoff loss to the Broncos, who went on to beat the Packers and claim the first of their back-to-back Super Bowls.

1992 NFC West

San Francisco 49ers (14-2, +195 point differential, best in league) and New Orleans Saints (12-4, +128 point differential, third in league)

This matchup of Nos. 1 and 3 wasn't quite as meaningful of a rivalry as the one between the Chiefs and Broncos. The Saints had the league's top-ranked defense, a fact that seems ancient given their defenses in recent years, and they played the Niners tough but lost both their games against San Francisco after winning the division the previous year, when the 49ers started Steve Bono at QB for six games. (To be fair, Bono went 5-1.) The 49ers were about to kick off their rivalry with the newly dominant Cowboys, who posted the league's second-best point differential at +166. Dallas beat San Francisco 30-20 in the NFC Championship Game, the first meaningful Cowboys-49ers matchup of the Jimmy Johnson era, and then promptly dispatched the Bills in the Super Bowl by 35 points. The Saints were beaten 36-20 at home by the Eagles in the wild-card round and didn't post another winning record until the 2000 season.

1987 NFC West

San Francisco 49ers (13-2, +206 point differential, best in league) and New Orleans Saints (12-3, +139 point differential, third in league)

They're back! This was the year when Jerry Rice scored 22 touchdowns in 12 games and somehow didn't win league MVP (on the AP ballot), which went to John Elway instead. Again, the 49ers arguably had another larger rivalry brewing in the Northeast. This time, it was against the Giants, who had knocked the 49ers out of the playoffs in the two preceding postseasons. The Saints held their own, though: They handed the 49ers one of their two regular-season losses, knocking Steve Young out of the game with a concussion before seeing Morten Andersen atone for a missed field goal that would have beaten the 49ers earlier in the year by hitting a game-winning 40-yarder. The competition didn't help either team, and both lost their opening playoff games.

1980 NFC East

Philadelphia Eagles (12-4, +162 point differential, best in league) and Dallas Cowboys (12-4, +143 point differential, second in league)

There is little arguing that Cowboys-Eagles was, and is, a long-standing rivalry, of course. This specific matchup was a weird one: The Eagles had been in second place behind the Cowboys in the each of the previous two seasons under Dick Vermeil, with a Week 15 loss to Dallas in 1979 handing the Cowboys the NFC East that year, but this wasn't the same Cowboys team. Roger Staubach retired after 1979, turning things over to Danny White, but the Cowboys didn't skip much of a beat. The Eagles instead improved, beating the Cowboys before losing the rematch in Week 17 after the division had already been decided. Philly won the deciding third game in the playoffs, beating Dallas 20-7 in a game played in temperatures as low as minus-17 degrees, only to lose to Oakland (+58 point differential) in the Super Bowl. The Eagles wouldn't win another playoff game until 1992.

1970 NFC Central

Minnesota Vikings (12-2, +192 point differential, best in league) and Detroit Lions (10-4, +145 point differential, second in league)

The most impressive pair of teams in one divisional race, coincidentally, came in the league's very first post-merger season. The Lions had a point differential 22 points better than that of the third-place Rams, and nobody else was in triple digits. Detroit also faced a far tougher schedule than Minnesota, so there's a good chance the Lions were every bit as good as the first-place Vikings. In all fairness, the Vikings handled their business against the Lions in the regular season, winning two games against Detroit in a three-week stretch during early November. (One of Detroit's two other losses came on Tom Dempsey's then-record 63-yard field goal.)

Neither team could turn its regular-season play into postseason success, though. The Vikings turned the ball over five times during a 17-14 loss to the 49ers, and the Lions suffered an even more ignominious defeat: They lost to the Cowboys in the first of two 5-0 games in league history.

That's a bit of a concern if you're a fan of today's Cardinals or Seahawks. There's not a big enough sample to say anything definitive, but at the very least, the anecdotal evidence doesn't seem to suggest that the sharper competition hones teams for success in the postseason. Rivalries are fun, and the games between the Cardinals and Seahawks will be highlights of the regular season, but both teams would probably be better off with a less impactful team looming in the West on the way to January.