This Thursday marks the beginning of the 99th NFL football season for scores of coaches, players, fans and referees. Only one of those groups can use video review to immediately reverse a bad decision.

Most sports fans are now familiar with the video-assisted review, or VAR, routine, though the rules vary slightly from sport to sport. Essentially, a referee can use video — available on the sideline or reviewed by a committee elsewhere — to re-watch a play and confirm or overturn a decision.

The goal, of course, is to make referees’ calls more accurate. However, University of Virginia Darden School of Business Professor Lalin Anik found that fans believe VAR leads referees to take more risks and make more mistakes.

Her research — which is awaiting peer review — specifically focused on soccer’s 2018 FIFA World Cup, which used video review for the first time this summer. Though it was not mandatory, World Cup referees could opt to use video review to determine if the ball crossed the goal line, if a penalty call was correct, if a red card was warranted or if cards were awarded to the correct player.

Anik, a self-admitted “sports-crazed” soccer fan, was curious about how the switch to video review impacted the fan experience. She used an online survey to show respondents three scenarios: one play that was clearly a penalty, one that was clearly not and one that was more ambiguous. In the ambiguous play, shown here, the referee used VAR to determine that French striker Antoine Griezmann, in blue, was fouled, leading to a penalty kick and a goal for France.

Anik asked some respondents to imagine that the referee made a call on the field without VAR, and others to imagine that he used VAR to overturn or confirm the decision.

Participants rated referees who used VAR — regardless of if the referee confirmed or overturned the decision — lower than those who did not. Fans believed VAR led referees to make more mistakes and take more risks.

“When they looked more closely at VAR scenarios, people started expressing more negative perceptions of the referee and their competence,” Anik said.

She speculated that the very act of stopping the game and questioning a call — even if doing so leads to the right call — could cause fans to perceive referees as uncertain or tentative. Additionally, in ambiguous situations when a referee needs the most assistance, fans viewed him even more negatively if he used VAR and overturned his decision, regardless of if he made the correct call.

“You would think VAR would increase fans’ confidence in referees,” Anik said. “However, seeing the referee stop, walk over and consult video replay could decrease confidence in their decision-making.”

Data from this year’s World Cup also backs up fans’ belief that referees make more penalty calls when they know they can fall back on video review.

In the 2014 FIFA World Cup, which did not use video review, referees awarded 13 penalty kicks. In 2018, they awarded 29.

“Referees can make riskier choices, knowing that they can then review the call on VAR to make sure they got it right,” Anik said.

This article originally appeared on UVA Today.