The line for Super Bowl XLVIII is trending ever-so slightly towards the Denver Broncos. After opening favored by just one point over the Seattle Seahawks, the Broncos have crept out to a two-point favorite, according to Oddsshark.com.
If that line holds until kickoff on Sunday, it will be the closest Super Bowl spread since 1982, when the 49ers and Bengals were a push in Super Bowl XVI. It doesn't have any room to increase if it hopes to retain that designation -- the Giants were a 2½-point underdog against the Patriots three years ago.
The NFL's increasing parity is illustrated through steadily shrinking Super Bowl point spreads. From 1986 to 2005, 16 of the 20 Super Bowl lines were seven points or larger. Since 2005, all but one of the spreads have been under seven points, and the last four (not including the game this Sunday) have averaged less than four points.
Historically, oddsmakers have done well setting the favorite -- the favorites have gone 26-19-2 against the spread all-time. But as parity has increased, setting the line has become more difficult. The underdog has covered in nine of the last 12 games.
The last time Denver played in a Super Bowl, they easily covered a 7½-point line with a 34-19 drubbing of the Falcons in 1999. The Seahawks couldn't beat the Steelers or the spread in 2006. Peyton Manning-led teams are 1-1 against the spread in Super Bowls. The Colts covered in a win over the Bears in 2007 but fell short of a 4½-point spread against the Saints four years ago.