A heavy silence greets this question while a TV screen shows footage of a Croatian defender hitting Brazilian full-back Marcelo with an ankle-high challenge during the Opening Match at the 2014 FIFA World Cup Brazil. Oscar Ruiz is not deterred, though: "Yellow or red? Let me play the incident again!"
The scene marks the beginning of the meeting with the Colombia U-20 squad and coaching staff, during which the former international referee will run through contentious incidents with his compatriots so as to educate the players about how officials apply the Laws of the Game. To start with, the atmosphere is hushed, constrained by the youngsters' shyness. This is nothing new: ever since FIFA introduced these now regular pre-tournament get-togethers ahead of Germany 2006, the players - especially the younger ones - have always taken a little while to get into the mood. But by three or four incident discussions later, a healthy debate has been struck up, albeit the expert takes the lead and always has the last word. Joining Ruiz in spreading the refereeing gospel to the 24 teams in New Zealand are several former colleagues: England's Howard Webb, New Zealander Mike Hester, the Irianian-American Esse Baharmast, the Tunisian Neji Jouini, the Italian Alfredo Trentalange, Denmark's Peter Mikkelsen, Alfredo Whittaker of the Cayman Islands, and Malaysia's Subkhiddin Mohd Salleh.
After once again replaying the images of Marcelo writhing in pain, Ruiz references the previous day's action to try to spark a reaction from the players. "Yellow or red or nothing? I asked the Argentina players the same question and the forwards think one thing and the defenders another. It's amazing how your mindset changes based on where you play." Some faint muttering is heard, the word "nothing" uttered sheepishly and almost apologetically. And indeed it turns out that this is the wrong answer. "People who say nothing... well, when they're on the receiving end of a challenge like this one, they change their tune," Ruiz remarks light-heartedly, yet firmly. "If it's even 10 centimetres higher, a tackle like this one can break a tendon or bone. It's a yellow-card offence and if it were 10 centimetres higher, it'd be a red".
When the screen displays a reckless lunge from another Croatian, Ante Rebic, on Mexico's Carlos Pena, a collective gasp fills the room. The youngsters can feel Pena's pain. There is no doubt this time: it is a clear-cut sending-off. The incident seems too obvious to warrant any discussion, but Ruiz soon explains why he chose it. The meeting is not only about helping players to understand disciplinary decisions and rules, but also about making them more aware of the possible consequences of their actions. In his words: "It's a dangerous tackle, it puts the [other] player's body at risk".
The ice has been broken now and, after a short break, the players well and truly warm to the task. Some may still be sporting gloves, and others hats that almost cover their eyes, to ward off the cold in Hamilton, but their body language has been transformed. Following some lively back and forth about "tactical fouls", we get to a subject that never fails to elicit strong responses, whether among the Real Madrid squad or Colombia's U-20s: hand-balls in the area. "He closed his eyes!" yells one player, sticking up for a fellow defender. "But he stopped the ball from getting through!" retorts an attacking midfielder. "Given the way he slid out, with his feet first, it's a natural way for him to fall," another centre-back muses. Ruiz listens and smiles. The different criteria used by players in different positions are laid bare, while impromptu groups of three or four are formed, each debating whether or not it is a hand ball and if so, whether it warrants a red or yellow card. The incident in question comes from a Manchester City match, in which a defender goes to ground to cut out a cross, his arm fully outstretched behind him as he slides along the grass. As it happens, the ball, which is headed into the middle of the box, strikes not his feet, but his hand. Ruiz poses a question and proceeds to answer it himself in emphatic fashion: "The Panama team doctor told me yesterday that the position the defender is in is not a natural one for his body. It's a penalty."
Further incidents follow until we reach the biggest flashpoint, one that resonates specially with this group: Mario Yepes's disallowed goal during Colombia's game against Brazil in last year's World Cup quarter-finals. The whole country was left up in arms about this decision by Spanish referee Carlos Velasco Carballo. Ruiz has touched a raw nerve and he knows it. He replays the incident once, twice, three times. The former official foregrounds the offside in the build-up and spells out why the Colombia players involved were clearly interfering with play. "As Colombians, it really hit home for all of us," Cafeteritos coach Carlos Restrepo told FIFA.com afterwards. "That's what emotion does: many of us thought the goal was valid and now we know it wasn't," he noted, before revealing a nugget that epitomises the point of the whole exercise: his players later took to social media to explain that the goal had been rightly chalked off, even trying to persuade their friends back home who begged to differ. "I think this is a really good idea," Restrepo added. "Players often play without a full understanding of the game and we [coaches] come up short because of a lack of knowledge of certain aspects of refereeing. It was a really good way to address concerns". The hearty round of applause the players gave Ruiz at the end says it all.