I am not watching this live, but on a projector inside a conference room at the Cooper Center Hotel in North Dallas, with all 14 of MLS's full-time referees. They're members of the Professional Referee Organization (PRO), which gathers every two weeks, in part, to review the controversial decisions from the previous games.

Chicago Fire attacker Gilberto streaks down the field after a bad turnover on a breakaway. With only the keeper to beat, he enters the box. An NYCFC defender nips at his heels. Gilberto goes down and the ball trickles to the keeper. No call by the referee. Play on.

This particular match, played on March 6, was refereed by Armando Villarreal, who, of course, is also in the room. At 30 years old, Villarreal is one of the youngest and fittest full-time officials in the league. Peter Walton, PRO's General Manager and a former English Premier League referee, sat in the front of the room and swiveled towards Villarreal.

The players have had a word or two at the referees' expense as well. One of the country's biggest stars, Michael Bradley, said in 2014, "The people at the MLS office in New York, when they talk about wanting to improve the league, the first thing that needs to be improved is the refereeing." One need only listen to Taylor Twellman during an ESPN telecast for a few minutes to detect the raw distrust most MLS observers harbor towards officials.

In his lyrical love letter to the game, Soccer In Sun and Shadow, Eduardo Galeano aptly described referees as eliciting the "only universal sentiment in soccer: everybody hates him." This is never truer than with MLS referees. Many keyboards have been pounded and articles written at their expense, including one on this website from 2014 with the headline " Incompetent Referees Are Wrecking MLS ."

The referees often argued during the film sessions, but on this particular play, no one disputed Villarreal's confession. "I couldn't see the hold, to be honest."

Villarreal didn't hesitate with his response. "Penalty," he announced to a room full of his colleagues and supervisors. Indeed, the Laws of the Game state, "A player must be sent off if he denies an obvious goalscoring opportunity by holding an opponent." With a clear path to goal, only the keeper to beat, the jersey pull, and the attacker going down, it was a clear penalty.

Walton is aware of the criticism. "My role is about raising standards and raising the numbers of proficient officials," Walton summarized a few weeks prior to the training camp. "Some people develop quicker than others. One mistake doesn't mean you're out."

PRO was founded three years ago as a partnership between MLS and the U.S. Soccer Federation to improve refereeing in North America. As Walton often says, with all the attention that goes into youth development for players, referees need much of the same tools and development to become professional quality. "One of the things that was not in place was a structure," PRO's sports scientist Matt Hawkey told me, referring not just to their physical fitness routines, but to the entire program.

With the formation of PRO, Walton has changed the culture amongst referees. Baldomero Toledo, who everybody calls Baldo—an unfortunate nickname as his hairline has thinned over time—told me that before PRO, refs would get together only twice a year, and when they did, they'd receive only infrequent and inconsistent messages from the league. Several of the referees recounted a time in the late 2000s when they were shown a tackle during a preseason meeting and instructed that such a tackle was not a red card offense. Then, during a midseason meeting a few months later, they were shown the same exact play and told it was now a red card. Toledo said it was "confusing."

That being said, there has been significant turnover in PRO's ranks. When Walton started in 2012, MLS had 37 referees. Now there are 22 center referees—14 full-time and eight part-time—five of whom were not part of the original 37.

Walton examined Villarreal's positioning and sightline on the fast break, a few seconds before the tug. In a matter of two seconds, Villarreal went from being perfectly positioned, right on top of midfield play, to being caught out after a turnover and long ball. As Villarreal attempted to catch up, a player got in his way, so he slowed to dodge him and lost his sight line.

Paul Rejer, PRO's training and development manager, rewound the tape, and we watched it over and over, breaking down a different element with each replay.

Villarreal's admission that he missed the penalty call is precisely why Walton insisted on holding these training camps in the first place: not because referees miss calls—referees will always miss calls—but because referees are a lot like players. They need practices, experience, film sessions, and training in order to maximize their performance. There's a teaching moment in every one that might prevent a similar mistake in the future and help referees, especially young, promising ones like Villarreal, develop as professionals.

One of the problems, according to Hilario "Chico" Grajeda, was that several different people would run each training session, and they'd all have different instructions. "One guy says he wants the house painted blue, then another guy comes in and says what the fuck did you paint it blue for?"

"However, think about that angle again," Walton continued as he transitioned into professorial mode. "Think about, I'm never going to get there, so I'm going to run across the field almost to see if you can get a better angle. Sometimes it's easier to sacrifice the distance to get a better angle. You might not get a better angle. You've done all this before. In that situation, happens to everyone in this room, where you get caught on a quick break. Something happens, somebody miscontrols the ball, someone has a brilliant pass, you get caught. If you get caught, think, shit, what am I gonna do? OK? Be, again, selfish. Burst through wherever you can, but try and get an angle."

"But you gave too much respect for the player in front of you to the detriment of losing sight of where you were trying to go to," Walton diagnosed. "You've got as much of a right to be on the field as the player. In fact, you've got more right to be on the field than the players. Nobody can send you off.

Younger referees, Toledo told me as we jogged around a soccer field for his training, have a tendency to cover more ground because they cannot read and anticipate the game as well (more than one referee referred to this as the headless chicken strategy). In the Laws of the Game, FIFA directs referees to run along a diagonal across the field. That alone won't cut it on the pro level, where everything moves too fast. Toledo, 46, has learned to recognize where a player is going to pass before he begins to kick. Now, he doesn't have to run quite as much, but he's still fit enough to keep up when he gets caught in a fast-paced game. By the final 10 minutes of our run, Toledo was easily sprinting ahead of me while I gasped for air.

Referees range in age from their mid-20s to mid-40s and live all over the country, from warm-weather climates to mountainous winterscapes. To ensure their training regimen makes sense, Hawkey looks at approximately 100 pieces of data per referee to monitor their performance and fatigue levels.

Now, each referee must pass a fitness test: a 150 meter run in under 30 seconds and a 50 meter walk in under 35 seconds, repeated 20 times. To stay in shape between tests, referees receive personalized workouts each day via an app from Hawkey, and fitness trackers keep logs of their activity.

Besides training camps, Walton, with Hawkey's help, has instituted strict fitness standards that didn't exist previously. Prior to PRO, referees were on their own in terms of working out and staying match fit; no small task, considering that many referees run as much as some players during the course of each match, yet tend to skew older than the players.

Which, of course, is the point. PRO tracks every decision a referee makes—whether they made a call or not, since even non-calls are a decision—through an outside company. "We look at every event in a game," Walton said. "And every event is every foul, every throw in, every offside, everything." Those decisions are then narrowed down to the calls that impact the game the most, to create a statistic known as a Key Match Incidences, or KMI.

When I asked Toledo, walking back from our workout, if he has improved as a referee since PRO's inception, he stopped mid-stride and turned to face me, in a stance familiar to anyone who has been on the receiving end of one his many red cards. Instead of reaching for his back pocket, he offered a resounding affirmative. Although he has refereed at various levels since he was a teenager in Mexico, the fitness standards put in place have gotten him in the best shape of his life. There's a body of research illustrating that as fatigue increases, accuracy and speed of thought declines drastically. If you don't believe me, run five miles and then try and solve a multi-step math problem. Toledo said, quite simply, being fitter allows him to make better decisions.

Walton has taught them to maintain a 20 yard distance from the ball at all times, which gives referees a close enough view to see the details but the peripheral vision required for the big picture. Nevertheless, there are several spots in the field—the penalty area, the center circle—where 20 yards can be tricky to maintain. Fitness and quick bursts of speed are prerequisites for effective officiating.

According to data shared by PRO, the referees have gotten better in the last few years. League-wide, incorrect KMI calls have decreased to about one per every five games, a 21 percent reduction from 2014. But, there is a huge range between referees. Walton and his team have found that referees tend to fall into three bands of ability: the seven best, the middle 10, and the bottom five. The top seven referees, the best of the bunch, missed only .09 KMIs per game in 2015, or about one call every ten games. The bottom five, however, missed a KMI about once every two games.

Given the small sample size, this roughly falls in line with PRO's numbers collected over the last few years. Seventy-two percent of warranted red cards were detected, meaning 28 percent were missed (they may have given a yellow card or a foul for a red card offense). Toledo in particular is often criticized for showing too many reds, but this reputation isn't backed up by the data. In 2015, Toledo gave a red card every four games—11th out of 18 referees with 10 games or more. The year prior, he was 12th out of 20.

About a week after the training camp, MLS referees came under some heavy criticism for the number of red cards they have given through the first three weeks of the season: 16 red cards through 42 games, a rate of .38 dismissals per game, according to ESPNFC . As always, most adhered to the time-honored tradition and assumed the referees to be at fault. But, Will Parchman of Top Drawer Soccer looked at each of the 16 red cards and found 12 of the 16 to be clear decisions, one or two very close calls, and a few mistakes. Walton held a conference call with reporters to defend his flock.

"They [the assistant referees] need to read the situation as well," Mark Geiger, one of MLS's most experienced referees, chimed in. "This is not a case where Armando's right on top of the play and it's all the way on the other side. They're—fine, it's fine to come on the mics and not raise the flag if he's five yards from it...[but] it's a breakaway situation, Armando's caught 25-30 yards away, that is an appropriate time for them to raise the flag."

Villarreal said he talked to the assistant referee after the game and asked him to raise the flag in the future. According to Villarreal, the assistant referee said raising the flag might present a different problem. What if Villarreal saw the play well and chose not to make the call? Then you have a damaging inconsistency where players and fans see the flag raised but no foul called.

Villarreal went on to explain that, as he turned toward the assistant referee to pivot back upfield, he saw the official had not raised his flag, so despite shouting "holding, holding" into the mic, he had not actually made any decision. Villarreal took this as a sign that perhaps the assistant referee wasn't 100 percent confident, and he felt he couldn't blow the whistle and show red since he didn't see anything himself.

Walton agreed, so Villarreal expanded on what happened. "He did. He did shout 'holding, holding.' But from where I was I just didn't see anything to call it and that..." Villarreal paused for a brief second and then held out his arms and touched his chest: "I put it on me 100 percent."

Back in the conference room, another referee, Jair Marrufo, added a new element to the discussion of Villarreal's missed call. "I think the AR [assistant referee] could help you with this."

One of the things that makes refereeing so difficult is that everyone believes they are one. Any call of even marginal controversy or import is met with protests from players and tens of thousands of fans in the building, all of whom believe they know what really happened—or, at least, know what they prefer to have happened.

After a full day reviewing dozens of calls with the PRO team, listening to conversations that sometimes lasted 20 minutes about a single play, I began to grasp just how complex some of these decisions can be. A player can suddenly dart in front of a ref's line of sight at the critical moment. A quick switch of the field can leave a ref 40 yards away from the play, sprinting to catch up. Interpreting a player's intentions, in the heat of the moment, sweat dripping from your face in the middle of your fifth mile on the day, isn't nearly as easy as making the call during the fifth slow-motion replay while you sit on the couch.

Walton interjected with a solution from his playing days. "My idea, whenever I was caught, I always said on the microphone, 'over to you' in terms of, you're in charge, you're refereeing the game for me at that moment because I'm too detached. Then when I felt like I was back in control in there, I'd say 'got it.'"

Refereeing is as much about fitness, positioning, and angles as knowing the rulebook. Photo by Mike DiNovo-USA TODAY Sports

Walton likes to say one in 30 calls will be so close that there is no single correct decision (there can, of course, still be wrong ones). This taps into a fundamental truth of soccer refereeing: it is, despite all attempts, an inherently subjective profession, held to an objective standard, mostly by people who have never read the rulebook.

Walton often echoes the popular sentiment that nobody pays to see the referee, but this is an oversimplification. The referee is a required fixture to maintain fairness, and fans pay to watch a fair game. True, fans don't pay to watch the referee run around the field, but they wouldn't pay to watch a game without one, either. We also pay, in part, to watch a desired outcome, a rooting interest, come to fruition. Refereeing has the illusion of simplicity because every fan already has a working paradigm for how all calls ought to go. Or, as Galeano wrote, "Scapegoat for every error, cause for every misfortune, the fans would have to invent him if he did not already exist."

To wit, one of the fiercest disagreements regarded a play in the 87th minute of the Red Bulls-Montreal game, where a defender put his arm out to shield the attacker who then goes down theatrically. Most of the room said it's not a penalty, but not everyone. Fundamentally, they couldn't agree on the severity of the push.

"From the defender's point of view, he's put his hands out to block," referee Alan Kelly argued.

"And that's OK? To block somebody by pushing them down?" Retorted Rejer. "Look at the actions of the defender."

"He's got body position and he's just using his upper body for me," Kelly replied.

After Walton asked the room if anyone else had a penalty, to a silent response, Rejer, somewhat dejectedly and completely sarcastically, resigned himself to the decision. "That's OK. The player's got possession of the ball and if it's OK for me to push a player to the floor, that's fine."

The room erupted into a series of side-conversations and rejoinders, not dissimilar to a bar room debate during halftime. Finally, the room settled, and Kelly added another element of consideration. "For me, you've got to take into account the way the player goes down. I think that's very theatrical as well. For the amount of contact that's been used there, he's literally thrown himself backwards onto the ground."

This went on for approximately ten minutes: point, counterpoint, new factor, and around and around. It was a healthy and spirited discussion, airing all the complex elements that go into a single decision. There's always plenty of time to discuss it afterwards, but only a brief window to make the call. Sitting in the conference room, watching replay after replay, I got the feeling the referees didn't mind the role of judgmental observers for once.

At the end of it all, Walton asked for a takeaway, a lesson to be learned, and the room went quiet.

"You have to look at the facts," Rejer tried one more time, to the good-natured grumbling of the referees in the room. "Is it a fact that he pushed him? Yes it is. Is it a fact that the guy goes down easily? You don't know. Nobody knows."

All the referees laughed, mostly because they thought Rejer was wrong, but also because, for them, "nobody knows" is never an acceptable position. They must always know the answer, even if there is no real answer. As I listened to the referees argue amongst themselves about whether or not this was a penalty, I realized the referee is a tragic figure. They're the only person on the field who can't win.

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During the entire discussion about Villarreal's call, not a single person in the room brought up the possibility that Villarreal inadvertently got the call right; that it wasn't actually a foul, a penalty, and red card. To every referee in MLS, this was a foul.