OCEANPORT, N.J. (AP) — With dozens of states rushing to offer legal sports gambling in the wake of this spring’s landmark U.S. Supreme Court’ ruling, will fixed games — or parts of games — become more common?

The four major pro major sports leagues and the NCAA have argued for years in court that expanding legal betting will lead to more game-fixing. The pro leagues have sought, unsuccessfully so far, to get a cut of state gambling revenues to increase monitoring. Democratic U.S. Sen. Chuck Schumer of New York recently proposed legislation establishing federal guidelines aimed at “protecting the integrity of the game” as well as protecting bettors.

Supporters of legal sports betting say that bringing an already popular illegal activity out of the shadows will make it easier to detect illegal activity. They point to the Arizona State basketball point-shaving scandal in the late 1990s, uncovered after legal bookmakers in Las Vegas noticed unusually large sums wagered on Sun Devils games. Six people, including two players, pleaded guilty to crimes including conspiracy and sports bribery.

Legal sports betting has been part of the landscape for years outside the United States, as have gambling-related scandals.

Soccer, by far the most widely bet sport worldwide, has confronted widespread match-fixing scandals often orchestrated by organized crime groups. FIFA, the sport’s world governing body, estimated in 2013 that organized crime was taking in as much as $15 billion a year by fixing matches.

Perhaps equally as susceptible to fixing is tennis, with thousands of matches played annually at out-of-the-way venues featuring players on the sport’s lower rungs. A report published in April by an independent panel found “betting-related corruption and other breaches of integrity have taken firm root” in the sport. It cited a decision several years ago by pro tours to sell live scoring data, which allowed sports books to offer in-game wagering. During this month’s U.S. Open in New York, bettors were able to wager on who would win a specific point, match or set.

In the four months since the report was issued, several men’s players have been suspended, two for life, and authorities in Belgium detained more than a dozen people on suspicion of match-fixing as part of a criminal probe dating back to 2015.

The uncovering of illegal activity shows that legal betting safeguards are working, said Joe Asher, CEO of London-based bookmaker William Hill.

“The illegal bookie isn’t picking up the phone and calling the FBI, he’s just going to try to get on the same side of the bet,” Asher said. “That’s the difference between the black market and the legal market that exists today.”

Still, the prospect of easy, legal access to sports gambling for everyone, athletes included, has many concerned.

“They’re going to create a bigger pool for more kids, and for more money to get involved,” said Jamall Anderson, a running back on the 1996 Boston College football team whose players were found to have bet against their own team. “It’s really going to create a big mess, I think.”

Anderson recounted his experiences in a 2016 book, “The Best Bet.” In an interview, he described a culture in which gambling was part of the daily routine.

“You went to practice and you got your spreadsheet in the locker room,” he said. “It was nothing to sit there on the sidelines and say, ‘Who you got this week?’ That’s what you do.”

College athletes aren’t strangers to wagering: A 2016 NCAA survey of more than 22,000 college athletes found nearly one-quarter of male athletes violated NCAA rules by gambling money on sports in the previous year.

And of the male athletes who had gambled on sports, 13 percent had wagered on specific game situations with in-game bets.

NCAA rules prohibit athletes, coaches and other athletic employees from gambling on sports, and individual schools sometimes bring in law enforcement officials or former players to help them understand the rules.

Will it be enough as laws change?

“Do you remember back when you were 18 to 20 years of age?” asked Minnesota athletic director Bob Vecchione, head of the National Association of College Directors of Athletics. “When people told you something, how much did it sink in? That’s what causes some sleepless nights.”

With inside information heavily sought in gambling, any tidbit — say, a student telling friends that his roommate, the star quarterback, just had a fight with his girlfriend — can take on greater significance, highlighting the need for more education, Rutgers athletic director Patrick Hobbs said.

“We’ll educate on a variety of scenarios and hypotheticals, and say, ‘Hey look, this may have sounded like an innocent question in the past, but now you have to be careful with that information,'” Hobbs said.

In the Arizona State hoops case, Las Vegas bookmakers reported suspicious betting activity when gamblers wagered about $900,000 against Arizona State in an early season contest against Washington. The heavy action caused sports books to change Arizona State from a 10½-point favorite to a 3-point favorite.

“You might write $30,000 or $40,000 total on both sides of that game under normal conditions,” Jimmy Vaccaro, then-sports book director at Mirage Resorts, recently told The Associated Press. “We wrote $560,000 on that game. The people thought the fix was in and ended up blowing their money.”