Patriots Rams Super Bowl
Detail of the Lombardi Trophy and the helmets of the New England Patriots (left) and the Los Angeles Rams prior to NFL Commissioner Roger Goodell speaking during a press conference during Super Bowl LIII Week at the NFL Media Center inside the Georgia World Congress Center on January 30, 2019 in Atlanta, Georgia. Mike Zarrilli/Getty Images

When the matchup between the New England Patriots and Los Angeles Rams became official, the betting odds saw a major change over the first 24 hours. L.A. was initially favored at some sportsbooks, but that wasn't the case for long.

The Super Bowl 2019 point spread now has the Patriots favored by 2.5 points, according to OddsShark, and that’s likely where it will stay until kickoff. Some oddsmakers raised the betting line to a field goal at one point, but only for a short while before dropping it back down a half-point.

Not only are the Patriots in the Super Bowl for a third straight year, but they are the Super Bowl favorites for the third time in a row. New England was upset by the Philadelphia Eagles 41-33 as 4.5-point favorites a season ago. Tom Brady and Co. famously came back from a 28-3 deficit in the 2017 Super Bowl to beat the Atlanta Falcons in overtime 34-28 and cover the spread.

Last year’s 4.5-point betting line matched the largest Super Bowl point spread of the last eight years. No team has been favored by more than that since 2010. This year’s game marks the first time the Super Bowl point spread is less than a field goal in four seasons.

In their nine Super Bowl appearances during the Brady-Belichick era, the Patriots have been underdogs twice. New England was a 14-point underdog against the then-St. Louis Rams when they upset the Greatest Show on Turf in 2002. The Patriots beat the Seattle Seahawks 28-24 as one-point underdogs in 2015.

The Rams were seven-point favorites when they beat the Tennessee Titans 23-16 in the 2000 Super Bowl. As the L.A. Rams in 1980, the team was defeated by the Pittsburgh Steelers 31-19 as 10.5-point underdogs.

Underdogs have had plenty of success in recent Super Bowls. The 2017 Patriots are the only favorite to cover the spread in the last seven Super Bowls. All six of those underdogs won outright.

All three of Brady’s Super Bowl losses have come when the Patriots were favored.

When the Rams beat the New Orleans Saints in the NFC Championship Game, it marked the first time all season that they were underdogs. The Patriots were underdogs for the first time this season when they beat the Kansas City Chiefs in the AFC Championship Game.

New England is 11-7 against the spread this season. Los Angeles is 9-7-2 against the spread.