A School Health File from Mexico and the Measurement Gap in Vietnam's Youth Academies

The file landed on my desk on a Tuesday morning in Shenzhen, tagged “football”. I opened it out of old habit: check the source, check the date, check whether it is actually football. Inside there was no team, no player, no scoreline. There was one university in Mexico, 35,000 students, 14 campuses, and a school-health screening table that I read four times before I had to put my coffee down.

Three in ten female first-year high-school students reported drinking alcohol. About half of those surveyed reported using some substance at some point. What stopped me was neither figure on its own, but the benchmark the university itself supplied: for that age group, the rate should be practically nonexistent.

Data is a map; the match is uncharted territory. I have mislabelled a great many files in 39 years on the job, and this time I kept the file rather than deleting it.

The university in the file is the National Autonomous University of Mexico, UNAM. To a football reader, that name means something else: UNAM is the parent institution of Club Universidad Nacional — Pumas UNAM, founded on 2 August 2026, once the starting point for Hugo Sánchez and Jorge Campos. That is almost certainly why the file carried a football tag. A classifier saw UNAM, saw Mexico, and assigned it the country's most popular sport.

The actual content sits in the university's high-school system: the preparatoria schools and the social-science centres, plus a tool called the Examen Médico Automatizado — an automated medical exam — applied to every incoming student. It is a mass screening programme running across 14 campuses and returning roughly 35,000 forms. The programme's spokesperson is Gustavo Olaiz Fernández, UNAM's Director General of Health Care. He speaks about intervening without stigmatising, about working with families, and about placing the data beside the national trend.

Technically, this is self-reported data. Students answer about their own behaviour. Anyone who has handled a questionnaire knows what that means: the true figure is usually higher than the recorded one. And the sample is large. At 35,000 forms across 14 campuses, the margin of error is small enough to be hard to dismiss.

I am not writing this to tell a Mexican story. I am writing it because when I finished reading, I recognised the same structure somewhere else: youth football academies.

An academy in Vietnam — PVF, HAGL, Viettel, Hà Nội, Sông Lam Nghệ An — operates closer to an educational institution than to a club. There are dormitories, academic classes, kitchens, doctors, two sessions a day. A twelve-year-old leaves his family and enters a system he will stay inside for at least six years. UNAM calls its subjects incoming students. Rename the category, and our academies hold comparable numbers; nobody calls them that.

And what we measure is very different.

I have a room in Shenzhen with two monitors. On them I watch V.League, the AFC Cup, and replayed U23 matches. Based on my experience tracking matches, I can talk about PPDA, about passes into the final third, about high-speed running distance. The GPS vest on a seventeen-year-old's back produces thousands of data points every session. We know precisely how much load a nineteen-year-old's hamstrings carried in the third week of pre-season.

We know almost nothing about the rest of him.

Put two tables side by side. The first: sessions, training load, recovery indices, soft-tissue injury risk. The second: how many trainees leave the system each year, why they leave, their psychological state at seventeen, eighteen, nineteen, and the share who retrain in another trade within three years of being cut. The first table is dense with numbers. The second is usually empty, or exists only in the head of a fitness coach who has since moved to another club.

Here is the point. The imbalance is not that we lack data on young players; it is that we collect data only on their usability, never on their personhood. A GPS vest measures what a club can sell. No sensor measures what a club will be held responsible for.

At forty-six, I worked for a Chinese sports platform and was required to file live updates every three minutes. I objected on the grounds of unverifiable data, then complied with the process anyway. Thirty matchdays taught me the difference between fast news and correct news. The lesson applies here: a metric refreshed every three minutes does not become true, and a gap with no metric still exists when nobody refreshes it.

In 2026 I was in Russia for the World Cup, and I was wrong. I read Brazil's 78% possession against Belgium in the quarter-final and predicted Brazil would advance. Belgium won 2-1 on the counter. I later pulled physical data from twelve knockout matches and found what destroyed my faith in glossy dashboards: in knockout rounds, possession share did not correlate with win rate. Since then I spend about five hours a day on replays and notes, and I do not read other people's summaries.

That same year, in Changzhou, a generation of Vietnamese youth players reached the AFC U23 Championship final in the snow and lost 2-1 to Uzbekistan in the last minutes. Nguyễn Quang Hải, Nguyễn Công Phượng, Nguyễn Tuấn Anh, Lương Xuân Trường, Vũ Văn Thanh — names that walked out of an academy that opened in 2026 with its first intake. The country did not sleep that night.

Six years later I sat watching V.League on a screen in Shenzhen and counting. Those names still play, still carry their clubs, still get called up. The generation behind them is far thinner. The second and third intakes of that same academy never produced an equivalent group. I have no official dataset to prove it — only a notebook of starting line-ups across several seasons, and one certainty: if UNAM can publish 35,000 screening forms, we have no comparable public release on how many trainees leave our academy system each year.

Pumas UNAM runs one of the oldest youth traditions in Latin America. The club uses the university itself as the intake system beneath it. If UNAM screens 35,000 incoming students, that population logically includes students who both study and play — a group the club has a direct interest in. The document does not say so. I will not attach a conclusion it does not make. I will only note that in a country where university football is tied to a professional club, the school-health system and the sports-medicine system speak one language. Elsewhere they speak two, and nobody interprets.

In my notebook there is a column I started in 2026: the names of young players the press called talents, with the last date I saw them in a V.League starting line-up. That column is longer than I expected. No agency publishes it. No season ends by summarising it.

That empty summer, I kept company with ghosts on the grass. In 2026 I was one of three reporters allowed into the training compound of a major club in Guangzhou. A 58,000-seat stadium held not one spectator. I recorded a centre-back taking 47 free kicks in 38-degree heat with nobody cheering. The coaching staff wanted a piece about fighting spirit. I wrote about loneliness. It ran because I had specific medical and psychological data behind it.

In Vietnam that same year, V.League was postponed and then returned with restricted stands. Viettel won V.League 1 for the first time in the club's history — a title awarded in a season no supporter could witness in full. I watched the decisive match on a stream running seven seconds late. In Shenzhen I learned that a screen cannot replace the stands. I learned a second thing too: at that same moment, somewhere, an academy psychologist was talking to an eighteen-year-old who had just been released, and that conversation was on no screen at all.

The transfer window makes everything louder. My inbox takes in a few dozen rumours a day: release clauses, fees, wages, agents. I grade rumours in three tiers by evidence — documented, corroborated, and single-sourced with no traceable origin. Most sit in the last tier. Release-clause structure and the wage bill are the real story, and the second real story nobody files is what happens to the seventeen-year-old nobody bids for that window.

Some will call the “football” tag a technical error. I do not. The tag is a diagnosis. If a classifier can mistake a school-health report for a football document, then football's information culture has taken the same shape as a public-health report: a screening table, a dashboard, a self-reported questionnaire, a benchmark used to apply pressure. Football and public health have evolved into the same genre of document. The confusion is not the algorithm's mistake; it is a portrait of how we describe football.

A different misreading: the assumption that adolescent risk is a male story. This is where the UNAM data is most counter-intuitive. The trend they recorded inverts the usual assumption: the female rate is higher than the male rate, and that higher rate is precisely what pushed the programme to alert status. Half of the students surveyed reported ever using a substance. Three in ten female first-years drink alcohol.

Now back to football. Youth safeguarding frameworks everywhere, Vietnam included, are designed around a default male risk profile: injury, performance pressure, grooming by gambling operators, mistreatment in the dressing room. Those profiles are real and necessary. But they rest on an assumption about who is most vulnerable, and UNAM has just supplied a 35,000-form sample suggesting that assumption may be skewed. An academy with one psychologist and one reporting channel built for male victims has put its fence in the wrong direction.

There is one more layer anyone in this trade must remember: self-reported data tends to be understated. Respondents hide behaviour society condemns. So three in ten and one in two are floors, not ceilings. Apply that rule to a dressing room and the true figure always exceeds the form. I write it that way even when it gets the piece called dry. In 2026, following Denmark after the collapse on the pitch in the 43rd minute against Finland, I wrote about a six-minute resuscitation protocol instead of a miracle. It was called dry, then quoted in a national parliament. Precise writing that stings carries its own weight.

This week I will call a friend at a northern academy about a nineteen-year-old whose contract has just expired. I will ask a question I have never asked in 39 years on the job: after he leaves, where does he go, and who goes with him?

I never run faster than the match; I only keep time until the final minute. At fifty-five, I think keeping time for a season already gone is part of the work too — even when nobody stays to hear the beat.