Week 3 in the NFL was a boon for Vegas bookmakers and a case study for one of the golden rules of football gambling

Casual bettors who enjoy putting a bit of money on NFL games are usually facing just slightly less than 50/50 odds at having a profitable day.

But unless you’re used to betting against the grain, it’s likely that Sunday was not your best day with your bookie, with upsets across the league shocking football fans.

The surprises started early, with the Jaguars putting an absolute drubbing on the Ravens in London, but it was the main slate of games that likely caused gamblers the most trouble. From the early afternoon until Sunday Night Football, 13 games of football were played. Eight games featured home underdogs.

Home underdogs usually present casual bettors with an opportunity that looks too good to be true. Take Sunday’s Bills-Broncos matchup. The Broncos came in as just three point favourites, meaning that if you wanted to bet the Broncos, they’d have to win the game by more than three points.

The Broncos were coming off a huge win over the Dallas Cowboys, with Trevor Siemian and company pouring 42 points on one of the marquee teams in the nation. Meanwhile, the Bills had just manage three points of offence against the Panthers and had to do everything they could in Week 1 to get past the lowly Jets.

To the casual bettor, easy bet! If the Broncos could beat the Cowboys by 25, surely they could cover three points against the Bills.

Instead, the Bills showed up, defended their home turf, and came out with the 26-16 win over Denver.

The lead up and outcome of this game serve as a great reminder of one of the most important rules in sports betting — always take a second look at the home underdog.

Now, please note, the rule is by no means “always bet the home underdog,” as there is no rule that is 100% in gambling or else we’d all already be rich. But chances are, if there’s a line that looks too good to be true, there’s a good chance that it is, and you should at the very least consider going the other way.

Case in point: of those eight home underdogs that played on Sunday, six of the dogs won their games outright, and the Lions came within inches of being the seventh. Had you blindly bet every home dog on the board, you would have been a healthy winner.

It’s important to learn from your past mistakes when gambling, as it’s one of the best way to start winning your money back. According to Jay Kornegay, VP of Race and Sports Operations at the Westgate Las Vegas SuperBook, Week 3 was the most profitable day so far of this young NFL season. While it’s a small sample size, as Kornegay told Business Insider, “Whenever the dogs cover the majority of the games with a few outright wins, that usually equates to a good day.”

For anyone who got taken to the cleaners last weekend, there’s five more home dogs on the board this week for your consideration. While there’s no such thing as a lock in Las Vegas, if you know a bit more than the average member of the gambling public, you and your wallet will likely be better for it.

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