LAS VEGAS — If you’ve followed sports betting for any time at all, hopefully you’ve heard the advice that, “There’s no such thing as a sure thing.”

Most bettors may have heard that, but a lot fell into that trap on Sunday when the Houston Astros, riding an eight-game winning streak, closed as -450 favorites at the William Hill sports books from New Jersey to Nevada and lost 8-7 to the lowly Baltimore Orioles, who were +370 at William Hill. The Orioles averaged +380 in Las Vegas with a high payout of +415 at the Circa Sports book. The Astros closed at the ridiculously high price of -550 at Station Casinos.

Someone — well, a lot of people — didn’t get the memo.

Unfortunately we don’t have record books for this sort of thing, but this was the biggest upset of the MLB season and the biggest one anyone in the business could remember, particularly by a home underdog. Usually when we see a baseball line approach -400, it’s with a dominant team hosting one of the dregs of the league.

In this case, the Astros were coming off a 23-2 rout of the Orioles on Saturday and sending Justin Verlander to the mound on Sunday. The Astros entered the game with the best record in the majors at 77-40 (.658), while the Orioles were 38-78 (.328), which was better than only the Tigers.

That was enough for bettors to believe there was easy money to made and the Twitterverse was full of comments such as, “The Astros can’t lose” and “The Orioles should just stay home.”

But upsets do happen all the time (Yankees fans probably will remember last year when Luis Severino was rolling along at 14-3 and lost to the lowly Royals after being bet up to -425 favorites at some books). Bettors need to realize when there’s value on even the ugliest of underdogs. As terrible as the Orioles are, after the win on Sunday, their record was 39-78 for a winning percentage of .333, so they had won one out of every three games played. Put another way, if you’re getting 2/1 (a money line of +200) on them, that would be fair odds.

But in this case you could have been getting closer to double that, so it was a good value bet.

You might think sportsbooks get burned when an upset like this occurs, but the opposite is true. The books were reporting that 80-90 percent of the action on this game was on the Astros, particularly when you take into account all the times the Astros were included in parlays and bet on the run line, where they were laying 1¹/₂ runs and were available at a cheaper price of between -280 and -300. Again, most bettors thought they were stealing money as the Astros certainly were going to beat the Orioles by two or more runs.

Not this time, as bettors who laid those prices now have to win several bets to recoup their losses.

In horse racing, these type of bettors are called “bridge jumpers.” They’ll bet a huge favorite to show, presuming that even if it doesn’t win, it’ll at least finish in the top three. Some will bet $100,000 to win $5,000, justifying their wager by saying that the horse is sure to at least finish in the money and the 5 percent return is better than they can get with any other investment (and in less than two minutes).

Don’t be a bridge jumper! Lose one time and you’ll have to win 20 straight times to recoup the losses.

Even if you don’t have the intestinal fortitude to bet ugly ’dogs like the Orioles were on Sunday, at least don’t be one of those who lays huge juice thinking you’re taking candy from a baby (and don’t do that either).

And the reason we’re writing this is because this isn’t the last we’re going to see of these huge baseball prices. On VSiN’s “Opening Lines” show on Sunday night, Matt Youmans was interviewing Ed Salmons, the Westgate Las Vegas’ VP of risk management and oddsmaking. Salmons said he was talking with fellow Westgate oddsmaker Randy Blum about a hypothetical matchup of the Astros (Gerrit Cole) versus the Tigers (Edwin Jackson) and they agreed the line would have to be at least -600, possibly -700.

So in the coming weeks, when we have top contenders such as the Astros, Yankees and Dodgers going against the bottom-feeders of the league such as the Tigers, Orioles and Marlins, we’re going to see these huge money lines again.

Find the times when the underdogs have value in pulling the upset and make sure you’re not following the lemmings off the bridge.