The Data Gap in V.League: When VAR Is Not Enough to Build Trust

Minute 88. A lofted cross from the right. The ball brushes the arm of the visiting centre-back inside the box. The referee points to the penalty spot, and the stands erupt like a boiler blowing its valve. Three minutes later, VAR steps in. During those three minutes, tens of thousands in the stadium and hundreds of thousands in front of screens were certain they had just seen the truth — but each of them saw a different truth.

I was sitting in that corner of the stand, a notebook in hand that has followed me through many seasons. What troubled me was not the final decision, but the gap between the moment the ball touched the arm and the moment the referee blew his whistle. Inside that gap there is no data. There is only emotion, memory, and belief. When data is absent, people fill the void with whatever they most want to believe.

Vietnamese football entered the VAR era in 2026, when V.League 1 first brought referee-assistance technology into a number of selected matches. It was not a leap, but a process. The Vietnam Football Federation (VFF) and the Vietnam Professional Football Joint Stock Company (VPF) worked with FIFA to train referees, install systems, and test step by step. The number of VAR-equipped matches grew season by season, but never covered the entire league. That is the reality of a competition where infrastructure remains uneven between stadiums, between matches, and sometimes between rounds.

That unevenness creates a paradox. VAR was born to reduce controversy, but when it appears in only a portion of matches, it plants a different question in the viewer's mind: why this match and not that one? That question does not belong to the laws. It belongs to trust. And trust, unlike law, cannot be repaired by citing a clause.

In the Laws of the International Football Association Board (IFAB), VAR may only intervene in four reviewable categories: goal or no goal, penalty or no penalty, direct red card, and mistaken identity. Outside those four, VAR has no authority. This is a limit designed on purpose, to keep the game from being chopped into dozens of stoppages. But this limit only runs smoothly when the officiating team has enough camera angles to establish that an error is 'clear and obvious.'

In V.League, it is precisely the word 'clear' that becomes blurred.

I once spent a month and a half cross-checking every VAR decision of a major league against the original law text. That work taught me one thing: errors rarely lie in referees not knowing the laws. Errors lie in referees having to conclude about an event they only partly see. When a passage of play has only two camera angles, the question 'did the arm make the body unnaturally bigger' becomes a philosophical debate rather than a measurement.

Law 12 on handball states clearly that the boundary between shoulder and arm is where the punishable zone begins. But to determine how far the arm left the body, one needs a sufficiently sharp projection. In top leagues, motion- and ball-tracking systems with multiple cameras record millions of data points per second, turning that question into a calculation. Where infrastructure is thin, that question returns to the human eye, and the human eye is never consistent between two people.

The core problem of VAR in V.League is not in the laws, but in the data gap between what the law stipulates and what the system can prove.

I call it the evidence gap. Once that gap exists, every stakeholder falls into the same trap: they are forced to conclude while the data is not yet dense enough. The referee concludes with his eyes. The fan concludes with emotion. The commentator concludes with speed. And in that race, the fastest to conclude is usually the loudest, not the most correct.

Based on my experience watching matches across different leagues, I have come to see that the quality of a VAR decision depends on three things, in descending order of importance: the number of camera angles, the quality of communication between the assistant referee and the referee, and only last, the individual competence of the referee. The first two are system. The last is human. When the system is weak, people blame the human. That is a costly confusion.

Let us step into one specific situation, the kind I believe will shape V.League debates in the time ahead: a goal disallowed for offside. Here, Law 11 states that a player is offside if any part of the head, body, or feet is in the opponents' half and nearer to the goal line than both the ball and the second-last opponent. Arms and hands are not counted, because the hand cannot score a valid goal.

The problem lies here: to determine which 'part of the body' has crossed the offside line, one needs an accurate line. Where semi-automated offside technology is absent, that line is drawn by humans. And once humans draw the line, the error is no longer a question of 'whether' but of 'how many centimetres.' At the speed of a striker breaking through, one-tenth of a second corresponds to dozens of centimetres. That is the distance between a goal and a whistle.

I once analysed a disallowed goal in a continental competition, rewatched the footage dozens of times, measured the defender's running angle, and realised a clause had been misapplied. That article came with fourteen illustrative frames, step by step. The lesson I drew was not 'I was right,' but: to overturn a ruling, you need a chain of evidence longer than the ruling itself. One image is not enough. A feeling even less so. Only a chain of evidence creates what I call weight.

Now let us return to the handball in the box — the most controversial situation of all. Law 12 does not punish every touch of the ball on the hand. The law punishes when the arm makes the body unnaturally bigger, or when a player scores with the hand even unintentionally. This means the same movement, the same ball direction, can yield different outcomes depending on the position of the arm. With two camera angles, we see 'ball touched the hand.' With five camera angles, we may see 'the arm was retracting.' Two opposite conclusions, one situation, differing only in the amount of data.

This is why I always tell younger colleagues: never assert certainty when you have only one angle. In a studio, when I once gave a wrong ruling on the handball law during a major match, I learned that lesson at the highest price. That mistake forced me to abandon one-directional assertion. I moved to a multi-branch structure: if clause X applies, the conclusion is A; if clause Y applies, the conclusion is B. That multi-threaded writing became my signature, but it was born from a scar.

My mistake on live broadcast was the foundation for a new system. And that system tells me one thing: in modern football, most controversies are not controversies about the truth, but about who has the right to define the truth when the truth has not been fully recorded.

Look at the structure of a VAR match. The referee makes an initial decision on the pitch. The VAR team in the closed room reviews it. If the VAR team judges there to be a clear and obvious error, they recommend the referee review the monitor. But the very moment the referee steps out to view the monitor is the most fragile moment, because he is then watching an image that has been cut, slowed, and zoomed — an image curated by someone else. He is no longer watching the match. He is watching a product of data.

In many leagues, experiments have begun to make the audio of the exchange between referee and VAR team public. That step targets trust more than accuracy. When viewers hear the reasoning behind a decision, they may disagree, but they understand that the decision did not come from arbitrariness. Conversely, a silent decision, even a correct one, is still doubted. This is a paradox Vietnamese football will have to face as VAR expands: to be trusted, sometimes you must accept being looked into.

I once wrote that an empty stand is the referee's most honest laboratory. When the roar of the crowd is gone, the match reveals its purest operating rules. The same is true of VAR. When we strip emotion away from a decision, what remains is usually a very specific technical problem: not enough cameras, not enough connectivity, not enough calibration standards. Those things can be fixed. Those things do not require a revolution, only a plan.

What is notable is that top leagues did not improve because they had more money. They improved because they standardised their processes. They have a clear set of criteria for each type of situation, regular training for VAR teams, and a public database of decisions. When a decision is controversial, precedent can be looked up. Where such a database does not exist, every controversy starts from scratch, as if the previous season had never happened.

This is the point I want to stress to Vietnamese football: the question is not whether VAR is good enough, but whether VAR has enough data to defend itself. A system that cannot defend itself will always need someone to blame. And the one blamed is usually the referee, even though he is only the last link in a chain of deficiencies.

I once watched a match in which a goal was disallowed for offside, followed by two days of argument on social media. Not one of the people arguing had enough camera angles. All of them had enough confidence. That is the most dangerous asymmetry in modern football: confidence always arrives before evidence. And when confidence arrives before evidence, a ruling is judged by feeling, not by a chain of logic.

There is a counter-intuitive angle I want to put on the table. Fans often believe technology exists to eliminate controversy. In reality, technology has never eliminated controversy; it has only moved controversy from the pitch into the closed room, and from the closed room onto the screen. What technology can do is turn controversy from an emotional quarrel into a verifiable debate. But to verify, you need data. And here, once again, we return to the gap.

The penalty law is not written for the taker, but for the reader of the shot. The same logic applies to VAR: the VAR law is not written for the referee, but for the interpreter of data. A good VAR team is not one that finds an error in every passage. A good VAR team is one that knows when the data is enough to conclude, and when it is not. The ability to say 'not enough' is a skill, not a weakness. But in a football culture that always demands an immediate answer, that skill is mistaken for hesitation.

That is why I believe the biggest problem for Vietnamese football in the VAR era is not technical, but cultural — how it converses with error. In many places, a referee's mistake is treated as an insult to be punished. That approach makes referees defensive, makes VAR teams overly cautious, and makes decisions safe rather than correct. A referee afraid of being wrong will not dare to be right. That is the price football pays when it turns error into guilt.

It took me years to understand that a mature football nation is not one without mistakes. It is one with a system transparent enough to turn mistakes into learning data. Every controversial decision, if recorded and analysed properly, becomes a brick for the next season. If buried in controversy, it becomes only a crack.

So what is needed to fill that gap? I believe there are three foundational tasks. First, standardise the minimum infrastructure for every match where VAR is applied, so that the number of camera angles is no longer a variable of luck. Second, build a public database of decisions, so precedent can be looked up instead of forgotten. Third, change how the media talks about error, from seeking who is responsible to seeking the systemic cause. These three do not demand expensive technology. They demand an organisational decision.

With the transfer window and a new season approaching, pressure on referees will only grow. Teams strengthen, expectations rise, and every point becomes more expensive. As pressure rises, the data gap does not disappear; it only becomes more costly. A wrong decision in a small match may be just a story. A wrong decision in a title-deciding match may be an entire season.

I still keep the habit of recording every controversial decision in a notebook, numbering the clause beside it, like the clerk of a trial that never ends. That notebook taught me that football does not lack opinions. Football lacks evidence. And as long as the evidence gap exists, every ruling will be judged by belief rather than by truth.

What I wish for Vietnamese football is not referees who never err. What I wish for is a system that makes erring learnable and being right verifiable. When the data is dense enough, the question is no longer 'who is right,' but 'what do we know.' That is the step from belief to evidence. And football, anywhere, only truly matures when it walks through that door.