Across the country and around the world, the hive mind of bettors and bookmakers has decided that the New England Patriots are 5 1/2-point favorites over the Philadelphia Eagles in this year’s Super Bowl.

That certainly seems reasonable, given that New England has a history of playoff success and the Eagles are missing their starting quarterback for most of the season, Carson Wentz.

>> The Line Is Moving: In the immediate aftermath of the conference championship games, the Patriots were posted as 6-point favorites. But people began betting on the Eagles, and the line moved quickly to 5 1/2. If you like the Eagles, you have the security that you are in a lot of company.

“I think it might come down a little bit more,” perhaps to 5, said Jon Campbell, sports analyst at OddsShark, a sports gambling information site. That action on the Eagles is coming mostly from fans and casual bettors, he said. “The Super Bowl typically is a public game. It’s a lot of recreational money.”

And of course just because people bet one way, that doesn’t mean they are right. Campbell cautions that particularly on the Super Bowl, early money can be a bad sign since it doesn’t always come from the smartest players.

But good for you if you got the Eagles plus-6.

>> The Patriots Play Close Super Bowls: The Patriots have been the dominant team of recent times, reaching eight Super Bowls in coach Bill Belichick’s 18 seasons. But despite all their good teams over those years, they never managed to blow out anyone in the big game. Their five wins have been by 3, 3, 3, 4 and 6 in overtime. Their two losses, both against the New York Giants, also were close, by 3 and 4 points. To cover the 5 1/2 this year, they will have to produce their most dominant Super Bowl victory yet.

>> The Eagles Are Thriving as Underdogs: Coming into the playoffs without Wentz, the Eagles got little respect as the No. 1 seed and were rated as underdogs at home against the Atlanta Falcons (by 2 1/2) and the Minnesota Vikings (by 3). But with the backup Nick Foles finding his groove, the Eagles won both games, blowing out the Vikings.

>> It’s a Big Number: The last eight Super Bowls all have had point spreads of 5 points or fewer. The last time a number was this big was in 2009, when the Pittsburgh Steelers were 7-point favorites over the Arizona Cardinals. (The Steelers won, but only by 4, and underdog bettors won.)

>> The Super Bowl Is an Underdog’s Game: Underdogs are 12-4 against the spread in the Super Bowl over the last 16 years. That includes the New York Giants’ victory over the 12-point favored Pats in 2008, and the Patriots topping the St. Louis Rams as 14-point underdogs in 2002.

And the other time the Patriots met the Eagles? In 2005, the Eagles lost by only 3 as 7-point underdogs.

>> It’s an Underdog’s Year: The playoffs this year have brought surprise after surprise. Underdogs are 5-4 on the field, and 9-1 against the spread. The only favorite to cover was New England, in its playoff opener against the Tennessee Titans. When Blake Bortles and Case Keenum are leading their teams deep into the playoffs, you know it has been an unpredictable year.

None of this adds up to a sure thing, or anything close to that. But if you’re thinking about betting the Eagles, know that many of the trend arrows are pointing your way.

© 2018 The New York Times Company