Vietnamese Swimming Lanes and the Missing Column of Data

The electronic clock on the scoreboard stopped at 2 minutes 01.84 seconds. The crowd applauded, the head coach nodded and wrote something in his notebook, and for most people in the stands, the story of that men's 200-metre freestyle final ended at that exact moment.

I was sitting in the sixth row above lane four, holding the result sheet handed out by the organisers. The sheet had six lines: name, year of birth, provincial or city team, heat time, final time, placing. Six lines for a two-minute race. Not one line told me whether the swimmer had gone out fast or slow over the first 100 metres, what his stroke looked like at the 195-metre mark, or how many strokes he took on the final length.

A small GPS deviation was enough to teach me that verification is everything. Here, the thing that needs verifying has not even been recorded.

After years of watching domestic swimming meets, from junior competitions in Da Nang and Hue to regional multi-sport games, the same discomfort follows me into every venue. Swimming is a sport measured to one hundredth of a second, and yet its data ecosystem is rougher than that of any other sport I have worked in.

Back when I sat in the analysis room of a football club in Nha Trang, I once spent weeks re-checking 14,000 GPS samples just to establish whether one defender had covered 1.2 kilometres or 0.8 kilometres at high speed. We argued about that number for a week. In Vietnamese swimming, we do not yet have a number to argue about.

What we actually record

Electronic timing has arrived at most national championships and high-level junior meets. The scoreboard links directly to the organiser's computer, and results appear almost instantly. In terms of hardware, Vietnam is not far behind the region.

The problem lies elsewhere. The software only records what the competition regulations require, and the competition regulations require very little: final time, placing, occasionally the heat time. A few meets do record 50-metre split times, but most of that data stays on the organiser's machine as a raw file. Nobody processes it, nobody publishes it, and after a few seasons it disappears along with the broken computer it was stored on.

Meanwhile, a 200-metre race at international level is dissected through dozens of variables. Reaction time off the blocks, usually between 0.60 and 0.80 seconds. Turn times across three wall contacts. Stroke count per length. Distance per stroke cycle. Underwater distance after the start and after each turn. Heart rate recovery after leaving the water.

Leading Asian swimming nations such as Japan and China record all of it. Not for the sake of archives, but because a coach needs to know where a swimmer is losing time. A swimmer who loses 0.4 seconds on every turn loses 1.6 seconds across the four turns of a 200-metre race, which is enough to drop from a medal to fifth place. Without measurement, we only know he swam slowly. As for why, we guess.

Diagnosis without data

This is where the story becomes serious for me.

Two swimmers who touch the wall in 2 minutes 01.84 seconds can be two completely different athletes. The first went out in 58.2 seconds over the opening 100 metres and faded on the way home. The second was half a second slower at the halfway mark but accelerated over the final 50 metres and finished strongest. The same result, two opposite diagnoses, two different training prescriptions.

The first swimmer needs aerobic base work and better pacing discipline. The second needs raw speed and a sharper start. With only a six-line result sheet in hand, a coach picks one of those two directions based on professional instinct. Instinct is not a bad thing. Most good coaches in Vietnam have made correct calls through intuition sharpened across thousands of training sessions. But intuition cannot be replicated, cannot be handed down, and cannot be verified.

A swimming nation does not upgrade its entire system through a handful of individuals with good instincts; it upgrades through data that a successor can still read ten years later.

I believe in numbers, but only after a number has passed three rounds of checking. The first round is equipment consistency: are the touch pads misaligned in the outside lanes, do the backup manual times match the electronic system. The next round is condition consistency: the same event swum in the morning and in the evening produces different results, so every comparison must sit inside the same time window. The final round is reader consistency: a data point has value only when at least two people look at it independently and reach the same conclusion.

At system level the gap is even clearer. A regional multi-sport games is usually prepared over two to three years, with qualifying-standard checks in each event. A swimmer who hits the A standard goes onto the priority list. But the A standard is usually a single time marker. It says nothing about whether that swimmer can hold form across three rounds in four days, even though most regional medals are decided by the ability to swim a morning heat and then return in the evening final with a faster time. That ability is measurable. We do not measure it.

The recovery table that swimming does not have

In 2026, when competitions were suspended by the pandemic, I spent seven months building a recovery index model for domestic footballers. The raw material was GPS data from 365 players across three seasons: high-intensity running distance, acceleration counts, injury history. The model predicted that the three teams applying the most intense pressing would see injury risk rise by roughly 23 per cent when the league resumed. One of those clubs cut training load by 15 per cent and lost no key players for the rest of the campaign.

Vietnamese swimming has no equivalent model, and the reason is not a shortage of experts. The reason is that daily training data is not digitised. Session volume, intensity distribution by heart-rate zone, rest intervals between repetitions, sleep quality among junior athletes — all of it lives in a coach's notebook, written in ballpoint pen, and stays there.

The consequence is longer-lasting than a single injury event. A 15-year-old athlete develops physically very quickly over two years. Without baseline data, we cannot separate natural age-related improvement from the effect of a well-designed programme. When performance suddenly drops, we cannot distinguish overload, an emerging shoulder injury, or simply a growth phase. Unable to distinguish, we handle it by waiting. Sometimes waiting is right. Sometimes waiting costs a talent a year.

Decoding what gets called a miracle

In Vietnamese swimming, almost every major result is retold in the language of miracles: an athlete who rose through willpower, a medal that came from something wondrous. I dislike that framing, not because it lacks emotion, but because it erases the trace of a process that can be repeated.

Croatia 2026 was not a miracle — it was xG written into history. Years ago, when the football world called one team's run destiny, I sat down and broke apart every match, and behind each moment labelled luck there was a structure: a deep defensive block, a goalkeeper performing above average, a favourable draw. All of it was measurable. Swimming is the same. A regional medal won by a Vietnamese swimmer over the past two decades has never been a single random event; it is the endpoint of a multi-year chain of training regimes, nutrition plans, and an overseas training stint taken at exactly the right age.

The problem is that the chain is never recorded. When the athlete retires, the chain vanishes, and the successor starts from zero with the same faith in miracles.

The economics of missing information

In 2026, a club in southern Vietnam invited me to assess a transfer target from the Thai League, priced at roughly 500,000 US dollars. My analysis covered 19 matches and showed that the striker had scored 18 goals from only 11.2 expected goals, and that 70 per cent of those goals came from set pieces, entirely dependent on the system around him. The leadership bought him anyway, reasoning that data cannot replace the eye for a player. He scored four goals in 20 matches and suffered two hamstring injuries.

I tell that story for a different purpose: to show that in Vietnamese sport, investment decisions are routinely made without baseline data, and the cost is paid not in one contract but across a whole four-year cycle.

In swimming, the investment does not look like a contract. It looks like a months-long overseas training camp, a visiting specialist, a nutrition programme, a recovery system, a heart-rate monitor, a dedicated strength coach. The total cost of one development cycle for a priority athlete can equal a substantial V.League contract. The decision about who receives that money, and at which stage, rests mainly on junior rankings and the judgement of the coach on the pool deck.

People see a contract; I see a ten-page probability table. The problem is that in swimming, those ten pages have not been written.

A counter-intuitive angle

Here I have to argue against myself, because this is the part most often skipped in any debate about data.

The assumption that collecting more numbers automatically produces better decisions is a false one. I have seen it fail in two directions. On one side there is overload: when a coach receives a thirty-metric report after every session, he stops reading and returns to whatever he trusts most, which is usually feel. On the other side there is model decay: my recovery model was built on 2026 to 2026 data, and when the world changed in 2026 its assumptions wobbled. A model is only valid under the conditions that produced it.

For swimming, that means we do not need thirty metrics. We need roughly twelve correct ones, recorded consistently enough to be comparable across seasons, and re-verified every year.

There is a third, subtler risk. Data can become a shield against accountability. A coach can say he followed the model. An administrator can say the numbers did not recommend it. At that point data stops being a tool for understanding and becomes a way to avoid judgement. Correlation is not causation, and a swimmer who posts a personal best after a programme change has not necessarily done so because of that change. He may simply have passed a growth phase, or landed inside the normal range of his own variation.

From the media side, coverage of Vietnamese swimming runs on a single axis: medals. A swimmer who finishes fourth with a personal best is written up as a failure, when in data terms it may be the biggest step forward that an entire age group has taken in two years. That kind of coverage is not only inaccurate; it creates pressure that pushes athletes and coaches away from publishing detailed data, for fear of being examined precisely where they are weakest.

A cheering culture is not measured by the volume of the shout, but by the frequency of patience. And patience with data means accepting that a model needs three to four seasons before it can say anything trustworthy, rather than publishing conclusions after two months.

Looking forward

Data does not tell stories; it records everything so that I can tell them myself. In Vietnamese swimming, the pen does not yet have paper to write on.

What I want to see in the next cycle is not one more medal. What I want to see is a fully published results file: split times at every 50 metres, turn times, stroke counts per length, and a column noting competition conditions. With that file, every coach in the country can read the same truth instead of each holding a private version of memory. If we are still left with six lines on a sheet of paper, we will keep sitting in the stands, guessing at what just happened beneath the surface of the water.