NFL Week 5 betting lessons: Worst team as a favorite this season? That would be the Ravens

The first four weeks of this season were won by the underdogs. Favorites got a bit of payback in Week 5, barely winning the week at 9-7.

Even though underdogs are doing well this season, only one team has taken three losses against the spread as a favorite without a win.

Surprisingly enough, the only team in the NFL that's 0-3 as a favorite is the 4-1 Baltimore Ravens.

The Ravens won and didn't cover on Monday night. The Indianapolis Colts were underdogs between 6.5 and 7.5 points, and they covered pretty easily. They were up 22-3 and even though they lost, there was no path for the Ravens to win by 7 or more once overtime started. (OK, they could have kicked a field goal and then got a pick-six, and surely some bettors were praying for that.)

According to Action Network's standings, the only other team that is three games under .500 against the spread is the Kansas City Chiefs, who are 1-4 against the number. The Chiefs' issues against the spread have been well documented by now. Is it possible there's betting value fading the Ravens going forward?

The Ravens weren't lucky to win on Monday night — describing anything regarding Lamar Jackson's phenomenal game as "lucky" would be inaccurate — but they needed a number of plays to go exactly right to beat a 1-4 Colts team at home. They needed a miracle to beat the Lions, who are 0-5. They lost to the Raiders. It's fine to win close games, but the high-wire act is unsustainable in the NFL.

The Ravens are 3-point favorites at home against the Los Angeles Chargers this week. Just beware that they might be overvalued and the market hasn't caught up to it.

Home-field advantage, still dead

Home teams struggled again in Week 5. They went 6-9 against the spread (we won't count the game in London). According to Covers.com, home teams are 39-41 straight up and 35-45 against the spread. Home favorites are 20-30 against the spread. There are 11 teams that are winless straight up at home this season, including the Patriots and Jaguars at 0-3.

In terms of betting, the disappearance of home field in the NFL might be the biggest story this season. Home field was at an all-time low in 2019, and it didn't matter again in 2020 but that was a strange season. If we expected it to bounce back in 2021, and bet it that way, it's time to adjust.

Who's going over or under this season?

There are no teams that have gone over in every game or under in every game. There are five teams that are 4-1 to the over through five games: Chiefs, Cowboys, Washington, Buccaneers, Rams. There are eight teams that have gone under in four of five games: Bengals, Patriots, Steelers, Broncos, Bears, Panthers, Seahawks, Chargers.

There might be nothing predictive in that because lines adjust. Against the spread and over/under numbers usually drift back toward .500. But you can take some clues from those lists of which teams have been disappointing on defense (Chiefs, Washington) or struggle to score on offense (Patriots, Steelers).