Home-field advantage doesn’t matter as much in the NFL playoffs as it does in the regular season. It matters more.
The finding comes as a bit of a surprise, given that one would expect the consistently higher quality of competition in the playoffs to level the home/road playing field a bit. In theory, one might expect the performance gap to narrow, and to whittle the leaguewide regular-season home-field advantage to something more modest.
Yet in the era of the 12-team playoff format that started in 1990, and spanning into the current eight-division format that started in 2002, home field has correlated even more often to wins in the playoffs than it has on an NFL-wide basis from September to December.
During the regular season, home teams from 1990-2015 enjoyed a .579 winning percentage. In the playoffs, that shot up to .673. In the eight-division structure — which more frequently has pitted so-so regular-season division winners against wild-card teams that often had superior regular-season records — the jump is less extreme, going from .573 to .621.
That said, if one ignores the wild-card round (where, on occasion, the underwhelming winner of a mediocre division hosts a superior wild-card team), the winning percentage of home teams in the playoffs since 2002 jumps to .679 — meaning that the home team wins about 10 percent more often in the division and conference rounds than would a typical team in a typical regular-season game.
In a more limited survey, the last three Super Bowl champions (the 2015 Broncos, 2014 Patriots, and 2013 Seahawks) all entered the playoffs as the top seeds in their conferences and won a pair of playoff home games en route to the Super Bowl. No team since the 2010 Packers has won a Super Bowl without playing at least one home game.
As much as any team, the Patriots are aware of the merits of playing on home turf. New England is 18-3 (.857) at home in the 12-team playoff era, including 15-3 during the partnership between Bill Belichick and Tom Brady.
In essence, against better competition, the Brady/Belichick Patriots have managed to be nearly as dominant at home during the playoffs as they’ve been during the regular season (101-19, .842 from 2001-15). It is not a coincidence that the Patriots have reached the Super Bowl in four of the five years in which they earned the top seed in the playoffs.
Of course, the reason for New England’s frequent advance through January goes beyond the mere fact that they’ve had home field and is a reflection of the fact that they’ve been good enough to earn the top seed.
There are considerable potential benefits to playing at home (though many are subject to dispute), including: environmental and climate factors such as Denver’s altitude and New England’s wintry weather; crowd noise that disrupts signal calls for a visiting offense, as seen in part through Seattle’s nine-game home playoff winning streak dating to the 2005 season; travel fatigue and lost preparation time; and the tendency for referees to make more favorable calls for home teams than visitors.
Yet the success of home teams in the playoffs likely is an indicator that the top seeding reflects the relative quality of teams.
In other words, the team with the better record is most often the higher seed and hence the host of the game. Home field is earned, and not — as is the case during the regular season — random. The 10-6 winner of a dismal division doesn’t host a 14-2 top seed in a win-or-go-home scenario.
As such, it makes plenty of sense that the merit-based home-field system plays out differently in the postseason than the regular season.
When superior teams have home-field advantage, they usually do a fairly impressive job of capitalizing on it, whether in the regular season or playoffs. Since 1990, top conference seeds have accounted for 27 of the 52 teams (52 percent) in the Super Bowl. The Super Bowl winner has been a No. 1 seed 12 times (46 percent) during the 12-team playoff era.
All of that underscores the significance of what the Patriots accomplished in laying claim to top-dog honors in the AFC. They didn’t guarantee themselves a place in Houston, but they’ve provided themselves with every conceivable advantage in getting there, including the ability to play inhospitable hosts in the coming weeks.
Follow Alex Speier on Twitter at @alexspeier.