ATLANTA -- In the 40th minute of a match in late June involving Atlanta United and the Montreal Impact, midfielder Saphir Taider sent a pass toward center back Zakaria Diallo. Gonzalo "Pity" Martinez got in the passing lane, deflecting the ball into the air. As Diallo received the now-bouncing pass, United forward Brandon Vazquez arrived, stretching a raised foot to the ball, appearing to catch it and then follow through into Diallo's ankle. The defender went down, and referee Ramy Touchan blew his whistle.

"Yeah, yeah, yeah," assistant referee Corey Rockwell, located on the sideline near the play, yelled into his headset. "Card if you want it. Card. Card. Let's do it. Let's do it. Yeah." Touchan ran over to the point of contact, reaching into his pocket and showing Vasquez a yellow card.

In a small room high above the field, Tim Ford leaned forward in his chair, peering intently into the large monitor in front of him. It showed the play as seen from four different angles.

"Did he get the ball? I'm going to check it again, to make sure," Ford, the video assistant referee (VAR) for the match, said to himself and assistant video assistant referee (AVAR) Kyle Longville seated next to him. If Vasquez didn't get the ball before clattering Diallo's ankle, the laws of the game would allow for a potential red card.

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Ford hit a large red button in front of him, marking the start of his review, then hit another switch that opened a communication channel with Touchan and the other on-field referees. "I'm gonna double check this," Ford said to group. To do so, he needed the best views. The operator sitting next to him, who was looking at a screen with all 14 camera angles, dropped the "low-mid" camera view onto Ford's monitor. The VAR used his fingers to enlarge the image, then asked the operator if there was anything better.

Down on the field, only a few seconds had elapsed. As Diallo recovered, Touchan told a player that VAR was checking the play. "I had point of contact top of foot, top of foot," Rockwell said into his mic. To another player, he explained: "They're checking right now, too. They're checking. It's a yellow, but they're checking, OK?"

In the booth, Ford continued looking at the play. Twenty seconds had gone by since he started his check, and while he was beginning to feel that the call on the field was correct, he wanted to make sure. "I'm fine with it, but I want to see it in full speed, please," he said to the operator. "Playing full speed," the operator responded as the clip streamed on Ford's screen.

"We're still holding up play here," Longville noted for Ford, who was too consumed with replays to see that Touchan hadn't given the Impact the go-ahead to take the free kick. Seconds later, after one final full speed replay: "Ramy, this is Tim. Check complete." As soon as Touchan heard those magic words, he blew his whistle and the match continued.

It took 40 seconds from foul to "check complete." There was no need for Touchan to go to the pitch-side monitor; he had gotten it right originally. Another play reviewed efficiently and accurately.

Welcome to the world of VAR.

Major League Soccer's stated goal is to become one of the best leagues in the world. One way it hopes to achieve this end is by embracing new technologies like VAR. "This is something that's at the very heart of MLS: to be a world leader, to be innovative," Jeff Agoos, MLS senior vice president, says.

In 2014 and 2015, MLS ran experiments in three different venues to test whether there was time to conduct video reviews. A year later, bolstered by this experience, the league tested the review system on behalf of the IFAB and FIFA and became the first league in the world to put VAR in every game in late 2017. It hasn't been a perfect rollout -- players like Toronto FC's Jozy Altidore and Atlanta's Leandro Gonzalez Pirez have criticized the system and mocked the officials this season -- but VAR is here to stay in MLS and the wider soccer world. It was used in all the major summer tournaments, including the 2019 Women's World Cup, and will make its Premier League debut on Aug. 9 when Liverpool hosts Norwich to open the 2019-20 season.

VAR does improve accuracy. According to league officials, 94.4% of calls would be correct in the absence of video review. With video review, that number jumps to 98.4%. Better, yes, but still not perfect. Therein lies the rub. Video review takes time and alters the flow of the game. Fans, then, expect it to be correct 100% of the time. But it won't be, for reasons that are both technical (camera angles didn't catch the action) and subjective (the interpretation of different rules varies from ref to ref and league to league).

In an interview about the present and future of VAR, Professional Referee Organization (PRO) general manager Howard Webb talked about the latter issue. "I think [VAR] will evolve with the culture of how the game is played across the world for the more subjective manners," he says.

"Interpretation of a handball in the Premier League is different from what it is in La Liga. VAR should reflect that."

In short, it's very much a work in progress. Rules and regulations will be developed and refined so VAR becomes as accurate as possible. It will never be perfect, meaning communication is key both for fans and referees. MLS launched a Twitter feed to explain what is being reviewed, why and the outcome in real time. According to Webb, unlike some other leagues and tournaments (the Women's World Cup), MLS head refs always go to the monitors to look at a call. "Fans said it wasn't clear why that was happening," he says of the reason for the decision.

In the chaos of a video review, it's essential for the VAR to be a good communicator, too. PRO refs participate in simulators and try to standardize their language to facilitate this back and forth. "When you're on the field and you're in a delay situation, you're listening for one of two things: Check complete or on-field review," Mark Geiger, PRO director of senior match officials says. "When the VARs start explaining everything, it gets lost."

It was easy to see this in practice in the booth in Atlanta as Ford calmly and cooly explained to Touchan what he was checking. The VAR and his operator worked seamlessly to get the right views on the four-panel screen. Ultimately, Ford saw that the on-field call was correct and that there was no need for an on-field review.

After the match, Ford sat in the ref locker room in the bowels of Mercedes-Benz Stadium, and talked about those moments. "We checked the yellow card to make sure it wasn't over the line," he said. "[Vasquez] gets the ball and follows through, but he actually plays the ball."

"It's cool," he said, of working as a VAR. "To be honest, I think it's good for the game. That's why I enjoy it. It saves everybody from the headline."