The Data Gap in Vietnamese Swimming

On the night of August 12, 2026, I reopened the nine-dimension analysis sheet I had built for a piece on swimming. The technical column read N/A. The performance column read N/A. The competition-system column, the world-landscape column, the rules and anti-doping column, the athlete-career column, the risk column, the media column, the industry-ripple column — every one of them carried the same line: insufficient information, cannot assess. Nine sections. Nine times. I sat looking at that sheet for a long while, then realised it was telling a truer story than most of the analysis I have ever written. Without data, every conclusion is a fabrication. An empty sheet is more honest than a sheet full of wrong numbers.

But that sheet was not empty because I was lazy. It was empty because the input was empty. And for someone who makes a living reading numbers, an empty input is a symptom worth dissecting far more than any defeat. That symptom, in Vietnamese swimming, is not the problem of a single spreadsheet.

I have worked as a sports analyst for nine years, coming out of the betting side, specialising in swimming. My job is to turn a race into a verifiable string of numbers: stroke rate, distance per stroke, per-50m splits, the efficiency with which each turn converts into speed. But to do that, I need something Vietnamese swimming has never fully supplied: data broken down into individual 50-metre segments.

Picture how a swimming result reaches the public. The meet organiser publishes the final time, usually just the last number and the placing. The World Aquatics results database archives major international meets, with splits added for events timed by automatic systems. Domestic media carry that number forward, sometimes with a sentence describing how the race felt. Those three layers stack on top of one another, and the striking thing is that they almost never contradict each other on the final number — they differ only in resolution. We always know how many seconds an athlete took to touch the wall. We almost never know in which segment those seconds were made.

That is why I treat that empty analysis sheet as a document. It says that I have the athlete's name, the event, the meet — and still cannot conclude anything. I removed the final-time column from the model, and the model demanded an explanation from me.

To grasp how serious this is, place side by side three generations of swimmers who shaped Vietnamese swimming over more than a decade. Nguyen Thi Anh Vien, born in 2026 in An Giang, opened an era in which Vietnamese swimming barely existed on the continental medal map. Nguyen Huy Hoang, born in 2026 in Quang Binh, carried it forward with medals at the 2026 Asian Games in the distance freestyle events. Tran Hung Nguyen, born in 2026, closed a transition cycle with a gold in the individual medley at the 31st SEA Games held in Hanoi in May 2026.

Three names, three phases, one structure. And that structure is precisely what our published data cannot see.

Vietnamese swimming runs on an individual-dependent model: national results are carried by a handful of swimmers at the top, while the base of the pyramid is barely measured at all. While Anh Vien was competing, Vietnam's medal count at each SEA Games had a clear pillar. When she stepped away from the international lanes, that pillar shifted to Huy Hoang, then spread to Hung Nguyen. But if all I have is a medal table, I cannot answer the most important question in my trade: how wide is the gap between our first and second swimmer, and is it narrowing or widening?

That is a question a medal table can never answer, because a medal table counts outcomes; it does not measure process.

Based on my experience following races, I draw three mandatory cross-check sources for any piece on swimming. The first is the official result from the meet organiser; the second is the World Aquatics results database; the third is the athlete profile published by the national federation and domestic media. These three differ in nature: one is a competition result, one is a historical archive, one is an administrative record. Only when all three agree on a point do I allow myself to write an assertion.

With Vietnamese swimming, those three sources usually agree on exactly one point: the final number. Which means I know how many seconds an athlete swam, and I know the placing. I do not know whether a fast first 50 metres was tactics or a sign of misdistributed effort. I do not know whether a slow last 50 was fading fitness or a deliberate hold for the return leg. I do not know whether a young swimmer is improving through stroke technique or through base conditioning.

Every race sends a signal. The analyst does not decode it; the analyst listens. Our problem is that the signal is largely cut away before it reaches the listener.

The first consequence is that we cannot value a swimmer. In football, a young player can be priced through metrics, through minutes played, through transfer data. Swimming has no transfer market in that sense. The value of a Vietnamese swimmer is reduced to one crude quantity: medals. And medals are the worst possible index for valuing an athlete, because they depend on who else happened to be in the lane that day.

The second consequence is that we cannot forecast generational handover. When Anh Vien left the lanes, the right question was not who would replace her, but how many swimmers the development system had produced during the years she was competing. To answer that, I need data on the number of registered athletes by age group, on how many youth meets are held each year, on the average training hours of a swimmer aged 12 to 15. Vietnamese swimming publishes very little of that.

The third consequence, and the one I care about most as an analyst, is that we cannot distinguish real progress from nominal progress. A swimmer can break a national record at a domestic meet where the lane holds no comparable rival. That record is real as a number, but it says nothing about the gap to the continental standard. Without splits, without international race data placed alongside it, I cannot say whether that swimmer has moved closer to or further from an Asian Games qualifying slot.

The My Dinh aquatics centre in Hanoi hosts most of the important national meets. Those meets have electronic timing, published results, qualified officials. They lack exactly one thing that every advanced swimming system has: a per-50m split sheet that is made public and archived long term. A small technical detail, but it determines whether we can analyse or merely narrate.

I once thought this was swimming's problem alone. Then I realised it is the general problem of how we consume sport. We love the final result because it is easy to tell. We shy away from process because it needs data. A medal can make the front page in three minutes. A per-50m split sheet takes three hours to read and nobody shares it.

But precisely for that reason, my job has a reason to exist. If everything were already clear, nobody would need someone to read the numbers.

At this point I have to argue against myself, because that is the discipline I set for myself after the most expensive lesson of my career.

The most comfortable hypothesis is this: if Vietnamese swimming published full splits, if there were an open data repository, results would improve. That hypothesis sounds reasonable, and I think it is wrong because it reverses the causality. More data does not produce more medals. Data only helps us see more clearly what we already have. If what we have is a system short of standard pools, short of dedicated coaches, and short of a competition calendar dense enough to expose athletes to pressure, then complete data will only make that shortage more visible.

I have seen something similar in another field. When advanced metrics became widespread, people assumed that understanding a match better would help teams win more. In reality, teams had been winning because they had better players and better organisation, and then used metrics to explain their victories. Correlation is not causation. A swimming nation with good data and a swimming nation with good results usually travel together, but what comes first is money, pools, and teachers — not the spreadsheet.

In other words, the data gap in Vietnamese swimming is not the cause of the performance gap. Both are symptoms of something larger: the level of investment in this sport has not matched the medal expectations society places on it.

And I have to admit one more thing. Some variables cannot be measured, and they may be larger than every number I hold. Nerves before a final. A shoulder injury in the most important week. An unexpected event off the lanes. After a personal shock in my career, I added a whole section to every piece I write: a list of non-quantifiable variables, with a risk-adjustment coefficient from 0.8 to 1.2. I removed the word certain from my vocabulary. I speak only of low or high risk levels.

The analyst's duty is not to be right. It is to say what the data wants to say. When the data is silent, the right thing is to say that it is silent.

So which signals should be watched in the next cycle?

The first is the split question. If a national meet begins publishing per-50m times and archiving them, that will be a bigger turning point than any medal. The second is the age structure. We need to know how many swimmers in the 14-to-17 bracket are approaching the standard for continental meets, because that is the earliest indicator of the next handover cycle. The third is the calendar. The density of competition determines how many times an athlete is tested under pressure, and pressure is the one thing no spreadsheet can simulate.

The 2026 Asian Games in Aichi and Nagoya, Japan, opening on September 19, 2026, will be the nearest test. Do not wait until then to go looking for the data. By then, the data will only be the obituary of a cycle that has already ended.

I still keep that empty nine-dimension sheet on my machine. Not as a memento. But to remind myself that, in this trade, the worst thing is not having no answer. The worst thing is having an answer to a question nobody asked, based on a number nobody verified.