The Empty Data File and Where a Swimming Analyst Really Stands

At 6:47 in the morning, at a coffee shop on Nguyen Thi Minh Khai Street, I opened the attachment that had just landed in my inbox. A 1.2 MB file. A perfectly respectable filename, complete with a date prefix. Inside was a table of contents divided into nine sections, neatly numbered from one to nine.

I scrolled down. First information field: empty. Second field: empty. By the ninth field, still empty. No athlete name, no event, no time, no competition, no publication date, no source. A file weighing more than one megabyte contained exactly one thing: silence, carefully formatted.

My job is to read files like that and decide how much of them to believe. Sixteen years of watching this industry taught me that most of the work is not analysis; it is verification that there is anything to analyse at all. That morning, the answer was nothing.

Swimming is the harshest discipline among the measurable sports. Football hands me xG, PPDA, passing maps and heat charts. Swimming hands me a single number on a scoreboard, and occasionally a split sheet if the organisers bother to publish one. The gap between two medal places in the men's 100m freestyle at an Asian Games is often under two-tenths of a second. To explain those two-tenths, I need reaction time off the blocks, the 15-metre underwater segment, 50-metre splits, turn times at every wall, stroke rate and distance per stroke.

I remember the milestones of Vietnamese swimming. Nguyen Thi Anh Vien, born in 2026 in Can Tho, won eight gold medals at the 2026 SEA Games in Singapore. Nguyen Huy Hoang, born in 2026 in Quang Binh, took silver in the 1500m freestyle at the 2026 Asian Games in Jakarta with a time just over 15 minutes and one second. Those two milestones belong to two generations, two training cycles, two entirely different ways of working.

But when I open the results sheet of a domestic meet, what I get is usually only the final number. Fans see a performance. Analysts see a gap as long as a 50-metre lane.

A decent swimming dossier has to answer nine questions, and I built the framework for all nine years ago, after the summer of 2026 when football stopped and I sat archiving 2,400 Serie A matches across two decades to find the market's pricing bias. Swimming needs a similar framework, except that it has nothing to archive if organisers refuse to keep records.

The technical layer asks about reaction time, the 15-metre underwater segment after the start, the quality of turns at each wall, and the efficiency of every stroke cycle. Without those four data groups, I cannot say where an athlete won the race and where they lost it. The positioning layer asks where the number stands: world record, all-time list, or the current season ranking. A time of 15 minutes 01 seconds can be a continental medal in one decade and merely a final qualifying mark in another. Without a frame of reference, the number means nothing on its own.

The format layer asks whether this was a heat or a final, a domestic or an international meet, and whether it sits inside an Olympic selection cycle. The landscape layer asks who currently rules the event, how long the dominance has lasted, and whether any handover is underway. The rules layer asks about equipment regulations, eligibility rules and doping-test history. The career layer asks where the athlete sits on the curve: puberty, the acceleration phase, peak, or the maintenance phase. The risk layer asks about shoulder injuries, back injuries and competitive load. The narrative layer asks how far media expectations have run ahead of reality. The industry layer asks where a medal will flow next: the coaching market, pool investment, or sponsorship contracts.

Those nine layers interlock, and that morning's file collapsed all nine at once, because it was empty from layer zero.

Here I have to say plainly something this trade rarely admits: the greatest value of a data file lies in its empty cells, because an empty cell is the only thing that forces an analyst to say "I do not know". When the data is complete, anyone can build a fluent, confident story. When the data is empty, there are only two choices: invent, or stop. I stopped, and wrote exactly one line into the record: insufficient information to assess.

That was also the moment I realised the bottleneck in Vietnamese swimming sits in the bookkeeping, not in the talent. We have athletes, we have coaches, we have pools, but we do not have the habit of record-keeping. A domestic meet ends, the scoreboard shows the times, the organisers save a PDF, and that is that. Nobody stores reaction times. Nobody stores 50-metre splits. Nobody stores the count of slow turns. Ten years later, when an analyst wants to answer why this generation is slower than the last over 100 metres, he will open the archive and find exactly what I found that morning: silence, carefully formatted.

During the transfer window I still keep a section of my own called dossier screening. In football, that section once stopped a permanent deal for a striker purely because his expected-goals-per-match figure was far below the level the media had inflated him to. In swimming, that section remains blank, and it is blank not because there are no swimmers worth watching. It is blank because there is no data to screen against.

The whole industry is chanting in unison that data is king. I hold the opposite view, and I hold it deliberately. A number is only worth as much as the honesty of the person reading it. Football taught me this with a line I still use when training new staff: PPDA is not a number, it is a confession. Swimming has its own version of that line: a finishing time is a confession about the entire training process, but it confesses very little about the race itself.

Numbers do not lie, but they know how to hide things. A time of 52 seconds in the 100m freestyle can be the result of an excellent start compensating for a fading finish, or of a blistering finish compensating for a bad start. Two scenarios, one number, two opposite training directions. If I have only the number and no splits, every recommendation I make is a guess dressed up in terminology.

From a market perspective, this honesty is taxed heavily. Loud rumours always travel faster than quiet facts. One line reading "insufficient information to assess" generates no page views. A bold prediction does. That is why most sports content chases emotion, and it is also why careful readers hold a long-term edge: the market misprices the blanks. That Saigon summer, I learned that data also needs watering. Without water, it is just a dry spreadsheet.

The next Asian Games, in Aichi-Nagoya, Japan, will be the first time I open a swimming dossier with a new item at the top of the list: checking whether the organisers publish full split sheets or stop at finals times. Then comes the question of whether domestic meets will add a reaction-time column to their official records. And finally, whether anyone in the industry will bother to keep the files that most people dismiss as useless.

That empty file is still on my hard drive, undeleted. It is the only blank I keep on purpose, a reminder that this profession begins with knowing what you do not yet know. If someone next year asks why I did not issue a prediction for a particular event at the Asian Games, I will open that very file and show them.