Graphic: Which NFL playoff seeds succeed?

These QBs of No. 1 seeds surely will meet in the Super Bowl. Or maybe not ... ? Kevin C. Cox/Getty Images

NFL teams fight all season to sew up home-field advantage in the playoffs. This year, the Atlanta Falcons and Denver Broncos earned the No. 1 seeds in the NFC and AFC, respectively.

But that doesn’t guarantee a Falcons-Broncos matchup in Super Bowl XLVII on Feb. 3. Far from it, in fact. Because, especially in recent seasons, home-field advantage has been negligible, at best.

Check out our infographic, which analyzes the success (or lack thereof) of No. 1 seeds -- and all NFL playoff seeds -- since 1975:

The NFL began awarding home-field advantage throughout the playoffs to each conference’s top team in 1975 -- before that, the sites of the conference championship games were based on a predetermined rotation, the same way Major League Baseball used to award home-field advantage in the World Series. (Yes, that’s right; the undefeated 1972 Dolphins had to play the AFC Championship Game at Pittsburgh because it wasn’t the AFC East’s turn to host. You think that had something to do with the rule changing?)

Thus, we’ve had 37 years of the NFL paving a path to the Super Bowl through the No. 1 seeds’ stadiums. How much of an advantage has that been? The results might surprise you:

• 20 of the 74 No. 1 seeds have won the Super Bowl -- 14 from the NFC, 6 from the AFC

• 20 No. 1 seeds have lost the Super Bowl -- 7 NFC, 13 AFC

• 14 No. 1 seeds have lost the conference championship game -- 8 NFC, 6 AFC

• 20 No. 1 seeds have lost their first playoff game -- 8 NFC, 12 AFC

That’s right -- in the past 37 years, winning the Super Bowl or losing your first playoff game has been a 50/50 proposition for a No. 1 seed.

Of course, home-field advantage can only help a team get to the Super Bowl, not win it, so the most valid measurement of its significance is that 40 of 74 No. 1 seeds have won their conference and advanced to play for the Vince Lombardi Trophy. That’s a tick above 54 percent -- decent odds, but certainly no guarantee.

Other findings of note:

• Since 2000, only two No. 1 seeds have won the Super Bowl -- the 2009 Saints and the 2003 Patriots.

In that same span, four No. 2 seeds, one No. 3 seed, two No. 4 seeds, one No. 5 seed and two No. 6 seeds have won the Super Bowl.

• In the first 12 years of the “home-field era” (post-1974), 10 No. 1 seeds won the Super Bowl.

• From 1984 to '96, when the NFC won 13 straight Super Bowls, nine of the champions began the playoffs as the No. 1 seed.

• Besides the 20 No. 1 seeds to win the Lombardi Trophy, the other 17 winners break down as follows: eight No. 2 seeds, two No. 3 seeds, four No. 4 seeds, one No. 5 seeds and two No. 6 seeds.

• The 1980 Raiders were the first wild-card team (a No. 4 seed at that time) to win the Super Bowl.

• The 1985 Patriots were the first team to reach the Super Bowl as a No. 5 seed, meaning they had to win three road playoff games.

• The only two No. 6 seeds ever to reach the Super Bowl -- the 2005 Steelers and 2010 Packers -- both won the Vince Lombardi Trophy.

*Note: Errors in this graphic have been corrected.

Infographic by SportsData LLC.