The 2024 NCAA men’s and women’s basketball tournaments are here.

That means it’s time to fill out a bracket, to suddenly become the biggest fan of a school you’d never heard of before this week, or to coat your body in team colors before every game (depending on your obsession level, of course).

For many Americans, it’s also time to place some bets.

This is “the most mainstream betting event of the year,” says David Forman, vice president of research at the American Gaming Association (AGA). “It used to be office pools and squares contests.” Now, with the explosion in legalized gambling across the US, he says, “people in almost 40 states have the ability to bet on the tournament legally, and we think they’re going to bet about $2.7 billion on the men’s and women’s tournaments.”

If that estimate has you staggering, you obviously don’t watch all that much live sports. Because if you did, you would have already heard from a slew of celebrities, like Jamie Foxx and Rob Gronkowski, selling you on the virtues of major sports books like BetMGM, FanDuel, and DraftKings. You also must’ve missed the headlines around the Super Bowl last month, when the AGA estimated that 67.8 million Americans would bet roughly $23.1 billion.

Sports betting is bigger than ever, and 2023 was the biggest year yet. But as more states legalize gambling, effective regulation hasn’t always kept pace. And it’s left some bettors wondering whether their bet will be honored.

Tournament betting is going to be wild

One of the reasons March Madness is such a big-time event for sports betting is the number of games being played — sometimes at the same time. In just the first four days of the tournament, there will be 48 games.

“The thing that makes it very bettable is the structure of the tournament,” says Jack Andrews, co-founder of Unabated Sports, a subscription service that purports to help sports bettors increase their chances of winning. “On the East Coast, the tournament starts at noon on Thursday [March 21]. And then you have game after game after game after game after game. It’s basically a betting bonanza for sports bettors from noon to midnight.”

In-game betting and prop bets are other forms of wagering that are very popular during the tournament, “especially betting the over/unders,” says David Vinturella, an instructor at the University of Nevada Las Vegas who developed and taught the school’s first ever semester-long course in sports betting this year and who previously worked for a major sports book.

He explains over/under bets like this: Betting the over is wagering that a team will score more than sports books’ predicted figure. Betting the under is the opposite.

Another well-liked prop bet Andrews describes is betting on the first team to score 15 points. “That is hugely popular in Vegas,” he says. “That’s not really betting on the game, you know — instead you’re just betting on which team gets off to a hot start.”

If you win, will your bet be honored?

With millions of people expected to place bets with sports books throughout the tournament, can bettors be sure they’ll be paid out if their long-shot bet wins big?

The answer to that question was a bit murky in the days before legal sports betting, when offshore sports books were the only game in town, says Andrews. “That’s the difference between the US and offshore sports books. If you have a problem offshore, the offshore sports book says, ‘I’m judge, jury, and executioner, and you’re out.’ Whereas in the states with regulated sports betting, [regulators] are supposed to make sure it’s a fair bet.”

Still, there have been stories recently about sports books in the US voiding bets that would’ve paid out big to bettors. The sports books use a clause in the fine print of their regulations saying that if there’s an obvious error with the odds in the bet (a.k.a. “palpable error”), they can cancel your bet.

Critics say this is unfair because the sports books have multiple chances to prevent a soon-to-be-voided bet from ever happening. “The bet is offered by the sports book, the bettor offers a wager to the sports book, and then the sports book accepts the wager,” says Andrews. “They had three chances to stop the bet from ever happening.”

Vinturella says that voided bets definitely happen, but that they are rare. “The process of getting a license and securing the license for a mobile sports betting company is not easy or cheap. So sports books don’t want to do anything that would jeopardize that license.”

Andrews agrees that most bettors will never have an issue with a sports book over a palpable error. “Ninety-nine percent of the time, sports books just eat the loss,” he says. But Andrews thinks regulators often have a “pro-operator” approach because “they’re funded by the operators,” and “they don’t want DraftKings to lose $1 billion because of something that should have never been out there.”

That’s why regulators should have clear sets of rules for determining what is and isn’t a clear mistake.

A good example is New Jersey, where the Division of Gaming Enforcement has a two-step process for deciding whether the error was palpable. Step one: Was the bet legal to begin with? If so, good. If not, the bet doesn’t count. Step two: Was there a risk of losing? If so, the wager stands. If there’s no risk, then the bet is voided because it must’ve been a mistake.

It’s that sort of easy-to-follow process that will let bettors trust regulators and confidently participate in the fast-growing billion-dollar industry — ultimately benefiting the sports books, too.

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