This is the second of eight entries in a Yahoo Sports series on the toughest jobs in sports. Click here to check out previous stories and a schedule for what's to come.
Panic surged through Horacio Elizondo late in the 2006 World Cup final as players from both teams encircled him and awaited his decision.
An Italian defender lay on the ground writhing in pain, clutching his chest and pointing at French star Zinedine Zidane, but Elizondo had been watching the ball and had no idea what happened.
The Argentinian referee asked his assistant closest to the play if he'd seen the incident. No luck. Elizondo asked his assistant on the far side of the pitch. Again nothing. Then, just as Elizondo feared he was about to make a mess of the most high-profile match of his career as a referee, the voice of a fourth official typically in charge of administrative duties crackled in his headset.
"It was the voice of an angel," Elizondo said. "Yes, the fourth official, Luis Medina Cantalejo, uttered in his very Sevillian, very Andalusian accent, 'I have seen it, Horacio. A really terrible headbutt by Zidane on [Marco] Materazzi. Again, a terrible headbutt.' And I said, 'Hey, hey, hey, stop. Calm down, Luis. Tell me a little bit about what happened. Who provoked whom?' Well, by the time I got to the spot, I knew Zidane was going to leave the pitch."
Elizondo's near-blunder on the most iconic call of his career illustrates how difficult officiating the highest levels of soccer can be even for the sport's best referees. Officials in every major sport must keep pace with world-class athletes half their age, make split-second judgment calls and brush off insults from hostile fans, but none have a more pressure-packed or physically demanding job than a referee in the World Cup.
To stay within 20 yards of the ball at all times, World Cup referees must run about 8-10 miles per match — even more ground than most of the players cover. As a result, FIFA requires candidates for the job to pass a fitness test in which they must run six 40-meter sprints in six seconds or less apiece and finish 10 laps around a 400-meter track with an average running pace of 5:20 per mile.
Adding to the challenge for soccer referees is that they're more on an island than peers in other sports. For example, the NBA asks three referees to cover a court 94 feet long and 50 feet wide. In soccer, one referee is essentially responsible for calling any foul that occurs on a playing surface 16 times as big as a basketball court, though he does have the aid of two assistants who judge when the ball has left the field of play and when offside has occurred.
The low-scoring nature of soccer also magnifies the importance of any call that either creates or denies a goal-scoring opportunity. Whereas a bad call early in a basketball or football game is usually forgotten since the victimized team still has many chances to overcome it, that's not always the case in a sport like soccer that averages fewer than three goals per World Cup match.
"Of all the sports, soccer is probably the most difficult to officiate," said U.S. referee Brian Hall, who officiated a pair of matches at the 2002 World Cup. "A decision by a soccer official can have so much impact on a game. Penalty kick or no penalty kick? Red card or yellow card? Offside or no offside? And let's face it, because soccer is so low-scoring, those kinds of decisions that can lead to goals carry much more weight than decisions in other sports. Over a season, you hope the calls balance out, but at a tournament like the World Cup, sometimes you don't have time for that to happen."
Though being vilified after bad calls and ignored after good ones is the norm for referees in every sport, the pressure on officials at a World Cup is immeasurable as a result of the consequences of a missed call. The stakes are arguably higher than any other sporting event since it's held every four years, the pride of entire nations is on the line and more people watch it than even the Super Bowl.
More from the 'Toughest Jobs in Sports' Series:
• Introducing the series
• July 21: Manny Pacquiao's sparring partner
• July 22: World Cup referee
• July 23: Colorado Rockies pitcher
• July 24: Publicist for Alex Rodriguez
• July 25: Ice maker, Arizona Coyotes
• July 26: Baseball card shop owner
• July 27: NCAA enforcement staff member
• July 28: Professional gambler
In this summer's World Cup, a referee from New Zealand was the subject of death threats and a petition calling for his resignation after he wrongly disallowed a critical Bosnian goal and was photographed hugging a Nigerian player after the final whistle. Twelve years earlier, Italian fans sent Ecuadorian referee Byron Moreno a barrage of death threats and the country's cabinet minister labeled the official a "disgrace" after he disallowed a goal and handed out an unjust red card in the Azzurri's shocking round of 16 loss to host South Korea.
Fan furor in soccer is hardly limited to the World Cup though. Stories of fans charging the field to attack a referee or pelting the officiating crew with coins or eggs are common at both soccer's club and amateur levels.
In the most egregious example, a mob of Brazilian fans gruesomely quartered and beheaded a referee and displayed his head on a wooden stake last July after he stabbed a player who assaulted him during an amateur match. Even in the U.S., referees in Utah and Michigan have died the last two years as a result of injuries stemming from vicious attacks by amateur players irate over calls that went against them.
It's easy for Hall to empathize with referees who have been targeted by players or fans because he has been in their position. Though the Major League Soccer matches he worked seldom inspired that level of furor, Hall recalls a handful of scary incidents from his days as an amateur referee in the San Francisco area.
"I had to learn survival skills," Hall said. "I've been assaulted. I've been attacked. I've been chased to my car. I've been chased across a four-lane highway as I was running to hide in a supermarket. All those things have happened to me. That's part of what happens as you grow and learn the trade, but at the highest levels, I have been fortunate thus far."
How can men like Elizondo and Hall justify pursuing a career as a soccer referee despite the constant threat of violence or verbal abuse? Both say their passion for the job outweighs any potential downside.
Elizondo first dabbled in refereeing during a handball game while studying to become a PE teacher more than three decades ago. His professor was so impressed by his performance that he encouraged Elizondo to pursue a career as a referee.
"I didn’t really think of it as a possibility until one day, many years after the fact," Elizondo said. "I was walking down the street and passed by the AFA (Association of the Argentine Footall), where there was a poster that read, 'Refereeing Courses Registration.' I kept walking, but when I got to the corner, there was a red light, so I couldn’t cross the street. It was then that I remembered my professor and turned around."
Refereeing quickly became Elizondo's calling soon after he enrolled at the AFA. A passionate soccer fan who had dreamed of being Argentina's Attorney General before becoming a PE teacher, Elizondo liked that refereeing combined his love of sports and sense of justice into one job.
From the moment he decided to pursue refereeing full time, Elizondo made it his goal to reach Argentina's first division, to become an international referee and to work a World Cup. Twenty-three years after launching his refereeing career, he marked the final box on that checklist when FIFA selected him to officiate the 2006 World Cup in Germany.
From a controversial red card for England's Wayne Rooney, to a penalty kick awarded to France, to a disputed Switzerland goal against South Korea, Elizondo had an eventful World Cup even before Zidane's infamous headbutt. Still, red carding one of the sport's best players with 10 minutes left in the World Cup final will forever be what Elizondo is known for most.
Strangers still recognize Elizondo all the time because of that call and approach him to discuss the details. He and Zidane even had breakfast together in 2007 when they discovered they were staying at the same hotel in Spain. And he and Materazzi also crossed paths two years later in Panama when Elizondo was refereeing an exhibition match featuring Lionel Messi and other top South American stars.
"I was getting ready in the locker room when someone knocked the door, and it was Materazzi," Elizondo said. "He approached me with a smile, said hello, and asked if he could take a photograph with me. So he went to look for the camera and when he came back he had his whole family with him — his wife and his children. So I took pictures with him and all his family."
The Zidane call might not have been a moment worth memorializing with photos for Elizondo were it not for the input of the fourth official on his staff. More than 300 million people worldwide watched that 2006 Final and many of them would not have been charitable to Elizondo had Zidane gotten away with the vicious headbutt.
Fear of making a high-profile mistake like that often hounded both Elizondo and Hall in the hours leading up to the start of World Cup matches they worked. Both men knew the many challenges of their job and the consequences of an ill-timed blunder.
"Before any match, you always have these feelings of nervousness and anxiety," Elizondo said. "Fear of making a mistake, fear of being misunderstood, and fear of failure. In my personal experience, I always faced a fear of making a mistake and had to work hard to cope with it."
Carolina Casares, Editor-in-Chief of Yahoo! Hispanic Americas, contributed to this report.