NFL bettors learned a lesson Sunday — don’t try to game Mother Nature.

With an eye on weather forecasts during the week that predicted strong winds at a number of game sites for Sunday and having those predictions confirmed by pregame images of inhospitable weather, the NFL betting public bet down the Over-Under line significantly on a fistful of contests.

By the time kickoff arrived for the early slate of games Sunday, the Over/Under betting line was driven down by 3 to 7 points from the open for contests played in Green Bay, Chicago, Buffalo, Baltimore, Cincinnati and Cleveland — primarily based in the weather.

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In those six games, the Over went 5-1. It was a rare instance of the bookmakers actually happy to see Overs come in.

“In the pregame shows they were showing some of the stadiums and there was bad weather,” MGM Resorts Director of Trading Jeff Stoneback said. “At the Pittsburgh game (in Baltimore) it was pouring rain. The public saw some of those weather situations and that drove the line down a little bit too much. For the 11 day games, it was 8-3 on the Overs (the Sunday night game of Dallas at Philadelphia was an Under). Usually, that’s not a good situation for the book but people were simply looking at the weather and in this case, it was beneficial to us.”

DraftKings Head of Sportsbook Operations Johnny Avello said factoring weather into either setting odds or making wagers is tricky business.

“Wind is something that is hard for a handicapper to make adjustments for when you’re a day out from the game itself,” Avello said. “You can’t look at wind in the middle of the week because things change so much. Rain is also a tough one because sometimes teams still score a lot of points in the rain. It’s snow that will keep down scoring. If you know a big Nor’easter is coming, those are the ones that you know will probably keep down the points.”

Upsets Boost Sportsbooks

Bookies enjoyed a profitable Sunday, and not just because the bettors outfoxed themselves by counting on the weather to bring in the Unders. Huge upsets by the Vikings over Green Bay, 28-22, and Cincinnati over Tennessee, 31-20, got the books off to a flying start. The Packers were 5-1 and a 5.5-point favorite over Minnesota, which was previously 1-5. Tennessee was also 5-1 pre-game and 7-point favorites over the Bengals, previously 1-5-1.

The Packers were a mammoth choice of the betting public. At FanDuel, 93% of the handle was on the Green Bay both for point spread bets and money line wagers. The Titans carried 76% of the points spread cash and 81% of the money line handle.

“The two games that were bet the most today were Green Bay and Tennessee, and when both of those lost straight-up so we had a good start,” Avello said.

Tua, Dolphins Come Through

Another upset that benefited the books was Miami over the Los Angeles Rams, 28-18, with the Dolphins starting rookie quarterback Tua Tagovailoa. Bettors counted on the rookie wilting in his first NFL start.

“The new quarterback wasn’t spectacular but they won,” Avello said. In fact, Tagovailoa was sacked and fumbled the ball away on his frst dropback but Miami’s defense and special teams essentially accounted for three touchdowns.

Perhaps, the most significant result Sunday in terms of future bettor handicapping was the Cincinnati triumph over the Titans. The Bengals, with rookie quarterback Joe Burrow, hae been close in many of its games. Despite being only 2-5-1 in the AFC North standings, the Bengals are 6-2 against the spread and have won with the point in six of their last seven games. That may mean that the Bengals are outperforming the expectations of oddsmakers and the betting public.

“In a bunch of games this year, the Bengals were hanging in there and looking improved but still losing,” Stoneback said. “Maybe they got over the hump here with this win over the Titans. I think that they’re a team that won’t make the playoffs this year but they have a good solid quarterback in Burrow and they’re headed in the right direction.”

Big Bets Odds & Ends

The Eagles’ 23-9 Sunday night win over Dallas, which was down to its third-string quarterback, was unquestionably ugly but one PointsBet customer was plenty happy after putting down $270,000 on Philadelphia for a first-quarter money line bet laying -270. The Eagles scored a touchdown with :02 left in the first quarter to take a 7-3 lead — salvaging the wager in the process.

At BetMGM, several $100,000 bets went the house’s way. One was a $100,000 bet on the Ravens (-4 at kickoff) against the spread that helped offset Pittsburgh public money in a game won outright by the underdog but still undefeated Steelers, 28-24. The others were $100,000 bets on San Francisco (1-point underdogs) against Seattle with the Seahawks winning, 37-27. Those big 49ers wagers offset the public lean on Seattle.