San Francisco opens as Super Bowl LVIII betting favorites over Kansas City at -2.5 points four years after Chiefs beat 49ers for Lombardi Trophy

Shortly after the NFL's conference championship games ended, the San Francisco 49ers began as Super Bowl LVIII betting favorites over the Kansas City Chiefs, with a -2.5-point spread. 

The less-than-field-goal confidence in the 49ers withered even further by night's end on the West Coast, with some sportsbooks making the betting odds nearly even, with San Francisco as a 1-point favorite. 

There is an increased focus on sports gambling surrounding the Super Bowl this year as the game will take place in Las Vegas for the first time. 

The amount of money taken by Las Vegas bookies for sports bets has is an average of $102.5 billion over the last four decades. 

The 49ers opening as betting-line favorites is not shocking, as they were the NFC's No 1 seed and had a better regular-season record than the Chiefs. 

If the line holds true, the Chiefs will be underdogs for the third straight playoff game.

Kansas City is 9-3 as outright underdogs with Patrick Mahomes as its starting quarterback. 

When the Chiefs defeated the 49ers in Super Bowl LIV, they entered the game as 1.5-point favorites.

The betting favorite has won 36 of the previous 57 Super Bowls, while underdogs are 28-27-2 against the spread. 

Kansas City was favored when losing Super Bowl LV to the Tampa Bay Buccaneers, but won as underdogs in Super Bowl LVII last season against the Philadelphia Eagles.

Entering the postseason, the Chiefs had 10-1 odds of winning the Super Bowl, their longest odds at any point this season. 

Three straight playoff victories against teams that at one point this season were considered Super Bowl contenders has lifted Kansas City right back to another AFC Championship, where plenty expected it to be in September.