When the Splits Table Is Empty: Vietnamese Swimming and the Discipline of a Conclusion

On the night of a SEA Games swimming final, the scoreboard returned a single line: total time. The stands erupted. The commentator screamed into the microphone. By the next morning, the whole sporting public was talking about "willpower" and "big-match character".

In Shanghai, in front of me, sat a spreadsheet with twenty columns: reaction time, 15-metre underwater time, turn time for every lap, stroke rate, distance per stroke, breathing rhythm, the gap between the two halves of the race. After that night, exactly one row was filled. Nineteen rows were empty.

The race is over, but the data is still talking. In Vietnamese swimming, most of that data was never generated in the first place.

A total time is a weak signal

A 1:59 in the 200-metre individual medley can belong to two completely different athletes. Swimmer A blasts the first 50 metres and collapses over the last 50. Swimmer B holds an even pace across three legs and accelerates on the freestyle leg. They touch the wall together; their potential is years of training apart.

The splits table destroys that ambiguity. Reaction time tells you about start reflex, a variable that is nearly saturated after the age of 20. Underwater time and breakout point tell you about push-off quality and dolphin-kick technique. Turn time is where the leading swimming nations take two to three tenths of a second off each other in short course. Stroke rate and distance per stroke are opposing variables: raising the rate usually shortens the stroke, and knowing where to trade one for the other is the whole craft of a coach.

Based on my experience watching matches and major championships, swimming data in Vietnam mostly stops at the most basic layer: total time, ranking, medal. Many domestic pools still time races by hand, and results are published as tables without splits. That means every argument about technique, about pacing, about whether an athlete has genuinely improved or simply met weaker opponents, is built on one single column.

That is where I started. The 2026 AFC U19 Championship had no data for me to analyse. It forced me to believe. Sitting in the stands in Shanghai at 18, I built a twenty-variable tracking sheet for every possession, and recorded a midfielder who touched the ball only 38 times but created 4 clear chances, while the press counted goals. My first article drew 5,000 reads overnight. What produced those reads was not good writing, it was data nobody else had.

An evidence chain from the lane

At the 2026 Asian Games in Jakarta - Palembang, Nguyen Huy Hoang took silver in the men's 1500-metre freestyle, Vietnam's first swimming medal at continental level. The press called it a historic moment and stopped at the medal.

The interesting part is the pacing structure. The 1500 metres is thirty laps of a 50-metre pool, and the race is effectively decided in the third 500. An athlete who goes out too fast pays 8 to 12 seconds over the final 300 metres; an athlete who holds rhythm and negative-splits the back half overtakes rivals in the closing sprint without the total time showing anything unusual. With splits every 100 metres, you see the whole story: who negative-split, who faded, who held even pace in bad water.

In short course it is even clearer. A 200-metre race contains seven turns. If swimmer A loses to swimmer B by half a second, that half second may sit entirely in those seven turns, not in the aerobic base. Without turn times, you cannot fix the error, because you do not even know which lap you lost.

For multi-event athletes, data is also a load-management tool. Nguyen Thi Anh Vien accumulated 25 SEA Games gold medals across years of racing individual medleys, backstroke, breaststroke and freestyle. Scheduling a workload like that only makes sense with splits telling you which event is eating into which, and which segment of the race is being drained.

The strongest federations pushed data into the public layer long ago. Every international result comes with 50-metre splits, reaction time and rule notes. That data does not reach the press first; it reaches the coach first, hours after the race ends.

Vietnam has an underused advantage: SEA Games publish splits. The data exists, but very few people scrape it out. As a result, after every Games the public argument returns to rankings and medals while the splits table sits silently inside a PDF.

The submerged part of the problem is the youth pipeline. National youth meets usually publish only final placings. A 14-year-old swimming the 200-metre individual medley may have a future in breaststroke while being grouped as a freestyle swimmer, simply because nobody has enough data to see where her strongest segment actually lies. Switching events two years late costs two years.

Vietnamese swimming also has a season paradox. Many domestic meets are held in short course because operating costs are lower, while the major international stage races in a 50-metre pool. An athlete can win a national title in a 25-metre pool thanks to good turns, then fail to hold position in a 50-metre pool because the aerobic base is not there yet. The splits table is the only thing that tells the two cases apart.

2026 and the lesson of having no data

I once thought data was the answer. 2026 gave me a better question. At that World Cup, Germany lost 0-2 to South Korea in the group stage. Pundits talked about bad luck after Germany dominated possession. When I rebuilt the data, Germany's expected-goals figure was lower than South Korea's, and the German back line exposed space behind the centre-backs 14 times. My article was taken down from a large forum for running against the mainstream press.

Then 2026 arrived, competitions stopped and match data dried up. I collected multi-season datasets and built a model predicting which players would break out after the shutdown, based on sprint speed, progressive passing rate and recovery indicators. It called 7 of 10 representative cases correctly. The lesson lay elsewhere: if you cannot record data, you cannot analyse, and when you cannot analyse, you tell stories. Good storytelling does not compensate for missing data.

The spreadsheet has no shirt colour, but I still hear the match through every column.

The counter-view: correlation is not causation

A swimmer who is 0.8 seconds slower after changing coach does not prove the coaching change caused those 0.8 seconds. Third variables are scattered everywhere: long course or short course, water temperature, altitude, time of day, taper phase, an illness before the meet, a long flight.

In a 50-metre pool, reaction time is barely a decisive variable in a final; focusing on it is using the wrong data. In a 25-metre pool it is the opposite. The same set of metrics, opposite conclusions, purely because of the unit used to measure the length of the lane.

Another trap is cross-era comparison. The high-tech swimsuit era ended with a cluster of frozen records, and many comparison tables still mix data from both sides of that line and call it progress for a new generation.

For Vietnamese swimming, the biggest trap is sample size. One SEA Games, one athlete, one good swim. Thirty laps do not create a trend. Serious analytical frameworks handle that situation in the opposite way to the press: they mark each category as insufficient information to assess, rather than filling the gap with speculation. It sounds unattractive. But in this trade, saying there is not enough data is a conclusion, and the most honest one available.

The transfer market does not buy players — it buys information about the future. Swimming works the same way when training centres and performance specialists are signed on the basis of data profiles. A profile with splits sells. A profile with only medals sells only emotion.

Signals for the next cycle

I am waiting to see who publishes the first splits table in Vietnamese swimming: a federation, a coach, or an independent analysis group. Recording data by hand on every lap needs no expensive technology, only a person in the right seat and a form with the right columns.

When the first splits table goes public, the axis of the argument in Vietnamese swimming will shift. The loudest voice will no longer be the correct one. Whoever holds the fullest dataset will be the one standing longest.

Tactics are a hypothesis. Every hypothesis needs a Korean night to be tested by fire.