From the Tuesday Morning Quarterback:
Since the current playoff formation was adopted in 1990, home teams in the divisionals are 45-11, an .803 winning figure. The home teams have just finished a bye week and relaxing in hot tubs as their opponents are out in the cold while being pounded. Usually the reason the home teams had byes in the first place is that they are better than the wild-card round teams. Home teams dominate the NFL divisionals, so check-mark them in your office pool. You don’t even need to know which team is playing! Just go for the home team in the divisional round.
A week later at the championship round, the home advantage dissipates. Since 1990, home teams in conference championships are 16-12, a .571 winning figure. That is nearly identical to the rate at which home teams win all games: During the 2004 regular season, home teams went 145-111, a .566 winning figure. At the championship round, nobody’s had the previous week off and the Super Bowl is just one “W” away. Players leave everything on the field at championship contests.