Home-field advantage has its unique qualities in each city.
Take Qwest Field in Seattle, for example. Architects designed the open end to give a view of the downtown skyline. As an interesting twist, the huge scoreboard on the closed end was positioned so those looking in from the city could see it. Not visible is the design's audible impact on the game.
On the open end of the stadium are two features that promote crowd noise. An area called the Hawks Nest sits in the end zone. Those seats are designed for the true fans. They are the lowest-priced tickets and seat the most rabid, vocal fans. Because they are bleachers, the Hawks Nest seats are constructed of metal.
One of the designs was to create noise, lots of noise. Ask the Giants, who had 11 false starts in a game at Qwest this season. At times, the open section of the stadium can be louder for opponents than the closed end. That's no accident.
The noise is amplified off the metal. If fans stomp their feet, it gets louder. And it's not just the cheap seats that help the Seahawks. Some of the priciest seats are below the Hawks Nest. Located right behind the end zone are the closest suites to the field in sports. You remember the area. That's where Terrell Owens took out his Sharpie and signed a football after scoring a touchdown on former Seahawks defensive back Shawn Springs.
Owens rewarded the football to a fan in one of those field-level suites. As it turned out, the suite, in part, was being leased by Springs and a few other Seahawks teammates. The fan who received the ball was a business associate of Owens and Springs.
Thanks to crowd noise and a good team, the Seahawks have the best home record (22-3) in the league since Week 16 of 2002. Home-field advantage helps.
No team knows that better than the Broncos. Their success at home has carried them to Super Bowls and has been with them for decades.
Invesco Field was built next to Mile High Stadium, which had metal bleacher seats. When Broncos fans stomped their feet in Mile High, the sound could be deafening. Invesco doesn't have the metal, but it still has the noise.
"You've got the crowd noise," Broncos cornerback Champ Bailey said. "It's hard for other teams. For one, our defense doesn't have to worry about jumping offsides as much. When you've got a lot of noise, offenses can't audible as much. It definitely worked."
Aside from the noise, the Broncos have the edge of playing a mile above sea level. Visiting teams always have a tough time adjusting to the thinner air. Players suck oxygen along the sidelines after plays, but the thin air affects each visiting player different. Some tire quickly. Some can't adjust.
The interesting aspect of the AFC and NFC championship games is that the visiting teams -- the Steelers and Panthers -- are experienced playoff teams and made the playoffs as wild-card teams. Each had to pull out two road victories to advance to the conference title games.
The Steelers blew home-field advantage at Heinz Field when they lost to the Patriots in the AFC title game last year. They were 15-1 during the regular season and had some of the loudest, most loyal fans in the sport.
"Last year when we had home-field advantage, it was kind of more of a distraction more than anything," Steelers receiver Hines Ward said. "We had more ticket requests. A lot of people wanted to come and watch. With us going on the road, we really don't have to worry about that too much. We just go out there and concentrate on football."
While that's nice to say, the Broncos and Mike Shanahan learned it's much better to be at home. They made the playoffs in 2003 and 2004 as a wild card and each year they were blown away by the Colts in the RCA Dome. Shanahan was taking criticism for not winning a playoff game since the retirement of John Elway. Sure, the Broncos made the playoffs after Elway retired, but they didn't win a division title until this season.
Thanks to home-field advantage, the Broncos, who haven't lost in Invesco this season, are in the AFC Championship Game. Bailey has seen many offenses struggle trying to fight off the noise of the Broncos' crowd.
"Getting checks and audibles to their receivers is the toughest thing," Bailey said. "You could see last week a couple of times. Tom Brady had to call time outs because he could not get the audibles in there. There were a couple throws he made that were in spots where receivers were supposed to be. Obviously, they were on the wrong page for a number of plays, and I think that's due to crowd noise."
No team suffered worse crowd noise problems than the Giants did against the Seahawks earlier this year. The 11 false starts cemented Qwest Field's reputation as one of the loudest stadiums in the league. The 24 false starts by opponents in Qwest Field this season was a league best.
Unlike Invesco, Qwest Field is at sea level, not far from the Puget Sound. The field proximity to the water also has its unique qualities that help the Seahawks. The winds are tricky toward the open end of Qwest facing the city. Jay Feely missed three key field goals in that Giants loss, but watching him kick field goals in that open end identified the problem.
Feely kicks the ball high, but at certain times of the season, the tricky winds push back high kicks toward the open end of the field. Josh Brown, the Seahawks' kicker, has somewhat adjusted to the problem. He's 9-for-11 in Qwest this season, including 4-for-6 from longer than 50 yards. In 24 career games at home, he's made 31 of 37 field goals.
However, the breeze at the stadium has affected Brown's kickoffs. It's hard to get the ball to the end zone on the open end of the field. He has to make sure he adjusts his field goals when kicking to the open end. It helps to kick the ball low, so it doesn't get caught in the wind.
It was easy to spot problems on field goals in Saturday's game. John Hall of the Redskins was lining up for a 36-yard field goal toward the open end. He was in the same spot Feely had missed his kicks earlier. Often, the flags don't pick up the direction of the breeze, so it's hard to gauge. Hall missed the field goal.
Another advantage for crowd noise came in the design of Qwest Field. Owner Paul Allen grew up going to Washington Huskies football games with his parents. Often, it rained at Huskies games. Allen had that in mind in making suggestions for the design of the new stadium. He didn't like being wet, so he suggested to get as many seats under cover.
Roughly 70 percent of the seats are shielded from the elements. A dry fan can be a loud fan, so Allen was able to get the best of both worlds for the Seahawks. The team gets to play in the elements. Most of the fans aren't affected, though, so they can be loud.
John Clayton is a senior writer for ESPN.com.