You Can Bet on Caitlin Clark Making Threes. The N.C.A.A. Isn’t Happy.

Iowa crushed its opponent to start the N.C.A.A. women’s basketball tournament this year, with Caitlin Clark, the sport’s shining superstar, finishing with 27 points to help the Hawkeyes cruise past Holy Cross. But for many, Clark blew it.

She scored six and a half points fewer than what many bettors expected she would, in what’s known as a prop bet, which allow gamblers to wager on outcomes beyond the results of the game.

As Iowa faces Louisiana State tonight, in a widely anticipated rematch of last year’s national championship, betting on an individual’s performance has increasingly been on the rise. How many three pointers Clark will make. How many assists Alabama’s point guard will accumulate. How many rebounds L.S.U. forward Angel Reese will pull down.

On FanDuel, one of the main gambling sites, there is a tab on the main page just for Clark’s games.

The wagering is the latest signal of the growing popularity of women’s basketball. According to BetMGM, there have been 2.5 times as many bets placed on women’s basketball as last year. Clark has received the second-most bets of any player, man or woman, in both events. Americans will legally wager $2.7 billion on the men’s and women’s N.C.A.A. tournaments this year, according to the American Gaming Association.

More gambling means more people watching. That has forced athletes and schools to deal with how many viewers now react to a missed shot, blown assignment or turnover.

On Wednesday, Charlie Baker, the president of the N.C.A.A., said he wanted to ban bets like the ones placed on Clark against Holy Cross.

“The N.C.A.A. is drawing the line on sports betting to protect student-athletes and to protect the integrity of the game — issues across the country these last several days show there is more work to be done,” Mr. Baker said in a statement.

Mr. Baker’s comments come amid a number of high-profile incidents involving gambling and sports. Last week, the National Basketball Association said it was looking into gambling irregularities centered on the performance of a Toronto Raptors player. The baseball star Shohei Ohtani has accused his interpreter of stealing money from his bank account to pay off gambling debts.

The N.C.A.A. has long expressed concern over the entry of legalized gambling in sports. In May, the organization commissioned a survey that found 58 percent of 18- to 22-year-olds had participated in sports betting. N.C.A.A. athletes and coaches are barred from placing bets on amateur, college and professional sports for which the N.C.A.A. has a championship.

Since 2018, when a Supreme Court ruling enabled states to legalize sports betting, 38 states and Washington, D.C., have adopted gambling. After decades of distancing themselves, many sports leagues have entered into agreements with sports books. Taxes from sports gambling are adding bigger chunks to states’ coffers, particularly as revenue from alcohol and cigarette taxes has fallen or slowed in many states in recent years.

That money has come with renewed risks, from threats to the integrity of the game to the welfare of the athletes playing them.

The N.C.A.A. said in February that Alabama’s baseball coach had supplied insider information to a gambler. More than two dozen athletes at the University of Iowa and Iowa State University were criminally charged for their involvement in gambling on sports. (The charges were later dropped.)

Anthony Grant, head coach of the men’s basketball team at Dayton University, said at a news conference in January that since Ohio legalized sports betting at the start of the year, his team had received a barrage of messages criticizing the team’s performance.

“There’s some laws that have recently been enacted that could change the landscape of what college sports is all about,” he said.

There are signs that many agree with Mr. Baker. Some states have already taken steps to limit prop betting. Iowa, for example, has banned prop bets on in-state teams, while states like Vermont and Maryland don’t allow prop betting on college athletes.

But Michael LeRoy, a professor and sports labor expert at the University of Illinois at Urbana-Champaign, said the N.C.A.A.’s efforts to crimp betting might not pay off. With hundreds of thousands of athletes spread out across the country, the N.C.A.A. may struggle to push policies that reign in gambling under state legislatures that see gambling as a positive economic force.

“They’re having a hard time regulating something that’s out of their control,” Mr. LeRoy said.

Jamey Houle, a sports psychologist at Ohio State University, has worked with the school’s athletes to help them manage the reaction to their performances, he said, as well as acting as a check-in to keep athletes from betting on games themselves.

“There are real consequences,” Mr. Houle said. “People can be threatened, their lives can be threatened.”

Armando Bacot, a player for the University of North Carolina’s men’s basketball team, told reporters last week that after the team’s second-round matchup, which was the most-watched game of the tournament through two rounds, he received more than 100 angry messages from people who had bet on him getting more rebounds. North Carolina legalized sports betting on March 11, right before the N.C.A.A. tournament.

“Going to a school like North Carolina, you never catch a break,” he said. “I order DoorDash and the driver is like, ‘Man, y’all messed up my parlay!’”