Then came her next big fight, Mayweather-Alvarez in September 2013, also at the MGM Grand.

In fact, it was one of the biggest fights of all time in terms of money and interest: Mayweather, generally considered the sport’s best pound-for-pound, would earn at least $41.5 million while Alvarez would take home at least $5 million. All told, it would eventually set a record with $18.6 million in ticket sales.

Unlike Pacquiao-Bradley, this was expected to be a much closer bout: Alvarez was only a 2-to-1 underdog, and he would have the support of the crowd. “Money” Mayweather’s appeal, no doubt, was his willingness to play the role of the villain. There would be no wild applause for the money-making champion.

After the fighters touched gloves, the consensus seemed to be that Mayweather was well ahead on the cards but not necessarily in dominating fashion. Ross scored five of the first seven rounds for Mayweather, while the other two judges had Mayweather winning six. The commentators for Showtime had similar scores.

But Paulie Malignaggi, a former welterweight champion and member of Showtime’s team, still thought neither fighter had truly distinguished themselves. “It doesn’t seem like each guy has grasped full control of the fight,” he said after the sixth round. Mayweather went on the win the seventh round, the final round upon which all judges would agree.

It was soon after that Ross’ scores started to depart from her colleagues at ringside. She gave four of the final five rounds to Alvarez, while the others had him winning two and three, respectively. The televised audience heard from a broadcasting team that began admiring the handiwork of Mayweather. The pro-Alvarez crowd, which had been wildly cheering for their undefeated fighter, grew silent down the final stretch. By the start of the 12th round, the outcome seemed no longer in doubt.

“Unless something dramatic happens here, it looks like Canelo Alvarez is on his way to his first loss,” Showtime commentator Mauro Ranallo said.

“Anybody objectively looking at this has to probably think he needs a knockout to win this fight,” Showtime’s Al Bernstein said.

At the sound of the final bell, two of Ross’ colleagues submitted scorecards awarding the victory to Mayweather. One had Mayweather winning nine of 12 rounds while the other gave Mayweather eight rounds, far from a blowout but enough for a decisive majority decision.

The CompuBox scores heavily favored the champ too: Mayweather connected on 232 of his 505 punches (46%) while Alvarez landed only 117 of 526 punches (22%).

Ross, once again, saw a different fight: She judged the bout a draw. Her tally didn’t change the result, but it was so discordant that it incensed almost the whole arena.

Mayweather’s response was to be expected: “What the fuck is this?” he exclaimed in the ring after the announcer read Ross’ scorecard. Alvarez himself said, “I recognize that he beat me.” And Alvarez’s promoter, Richard Schaefer of Golden Boy Promotions, called Ross’ scorecard a “disgrace.”

Atlas could barely contain himself in another incendiary diatribe on ESPN. “It speaks to the corruption of the sport,” he said on-air. “The criminals will be rewarded.”

“I try to use my platform to say what I think I have a responsibility to say,” Atlas told BuzzFeed months later. “I have suspicions about 90% of these judges. I don’t have to single her out. But she’s been involved in some questionable judging decisions, there’s no doubt about it.”

Actually, there is not even a fragment of evidence that Ross was on the take. There’s certainly no evidence of any major windfall at her home. “What money?” she asked, sweeping the air with her hand to point out her modest dwelling. “Where’s this trail of money at?” She adds, “There isn’t enough to pay me off, even if it was millions.”

Ross said Alvarez landed the heavier punches, and that was the difference in some of the closer rounds.

“Some of us judge the power differently,” she said. “I’m gonna go with the guy who landed the bigger punch if the rest of the round was equal.”

And Mayweather “never hurt Alvarez. … He landed good shots on him but he didn’t seem to physically affect him.”

Later, commission executive director Keith Kizer would defend Ross, whom he had recommended to serve as a judge for the bout. “Just because a judge’s scorecard ends up even, doesn’t mean the judge necessarily thought the fight as a whole was even. It could be that a judge has six rounds each for each fighter, but the six rounds she gave fighter B, they were really close rounds. That’s pretty much how it was last night,” he told USA Today.

It’s a reminder of how challenging it can be to score a fight. Judges have very wide discretion when determining the winner of a round. They consider clean punching, aggressiveness, ring generalship, and defensive skill. HBO’s Lederman, who worked as a judge for more than 30 years, relies on a much simpler standard. “If you can judge who did more damage in the round, that’s the guy you give 10 points to.”

But that can be complicated by fighting styles — especially those of boxers such as Mayweather, who throw fewer punches because they rely on their defense to frustrate opponents. There are also the limits of sitting on one side of the ring. To score a punch, a judge must actually see it. “Sometimes judges are sitting on the wrong side of the ring, and they’re missing punches,” Hall of Fame referee Joe Cortez explained. “And you can’t score what you don’t see.” Cortez, a friend of Ross’, has long proposed elevating the judges’ seats to provide a better view of the fight.

Given the vagaries of the scoring system, Ross can make a strong case that she made the right decision in the Pacquiao-Bradley fight. Yes, it flies in the face of conventional wisdom. But her card didn’t differ so much from those of her colleagues, and many observers agree that Pacquiao coasted in the second half.

Her case for the Mayweather-Alvarez bout isn’t nearly as strong, but, if she got it wrong, it’s understandable how she did: The early rounds were close, Alvarez is the harder puncher, and her sightline might not have been the best.

Certainly, Ross’ error — if it was that — in the Mayweather fight didn’t merit the personal attacks that followed. Not for someone with a virtually spotless record over the previous 21 years.

Her plight recalled that of Eugenia Williams, a female judge from Atlantic City who was roundly criticized for her scorecard in a heavyweight title fight between Evander Holyfield and Lennox Lewis in March 1999. Williams scored the fight, 115-113, for Holyfield while one judge scored it a draw and the other went, 116-113, for Lewis. Notably, Williams was the only judge to give Holyfield the fifth round, a round in which Lewis pinned Holyfield on the ropes with a barrage of unanswered punches for 45 seconds. The New York Times called it “one of the most controversial decisions in a big-time fight in recent history.”

Investigations into allegations that she was on the take turned up nothing. She was convinced that sexism drove at least some of the criticism. “They’ve never attacked an official like I’ve been attacked myself,” Williams told the Philadelphia Inquirer in April 1999. “I think it’s all blown out of proportion. … They don’t care what the other judges scored. They’re just focusing on me. I believe it was truly because I was a female.”

Williams didn’t work another fight for nearly five years. Ross knows that history. “She got pretty beat up,” she said.

Butch Gottlieb, a Las Vegas-based fighter manager and former inspector with the Nevada Athletic Commission, noted the difference in the reaction to Ford and Ross, who are both friends of his. He wouldn’t go as far as to blame sexism for the difference, but, he said, “Nobody mentioned Duane’s scorecard. Everybody zeroed in on CJ.”

“I was pretty disgusted by the whole thing,” said Nick Zagala, a close friend who lives in Pahrump. “They were just piling on. And I think it’s totally because she’s a woman.”

Ross hasn’t reviewed either of the controversial fights on television and has no plans to, saying that the changing cameras angles can’t duplicate the experience of watching the fight from her spot in the ring. She also isn’t a big fan of the television commentary. “They have a real bias in their presentation,” she said.