2,400 Hours of Swimming, One Spreadsheet: What Vietnam's Data Has Never Said About Swimming

In the summer of 2026 in Saigon, I sat in front of a screen with an Excel spreadsheet full of Hanoi FC's xG numbers. Two million dong in betting money had evaporated because of an emotional tip. I told myself: numbers don't lie, but they know how to hide something. Eight years later, I still keep that habit, but now what I filter is not football, but swimming — the sport I have pursued since my early days as a reporter for Thanh Nien Bao. Vietnamese swimming is in a strange phase. We have national records being set continuously, SEA Games medals being counted regularly, but when stepping onto the continental stage, results fall behind in a puzzling way. Public opinion often blames physique, training conditions, investment. But as someone who has spent 16 years observing the sports industry, I realize the problem lies deeper: we don't have a real data system. Look at how we operate. A Vietnamese swimmer after each practice session usually has their results recorded by the coach's stopwatch. Those numbers stay in notebooks, or worse, in memory. There is no system to analyze stroke rate, no data on distance per stroke efficiency, no metrics comparing with regional peers. We are swimming in the dark, and proud of medals that could have shone much brighter. I remember the 2026 World Cup, when I used manual PPDA to predict South Korea would beat Germany. PPDA is not a number, it is a confession. It told me that Germany's midfield was allowing abnormal pressing. In swimming, the equivalent of PPDA is analyzing rest intervals between distances, stroke rate changes in the final 50 meters, and how the body responds to competitive pressure. These data, in Vietnam, barely exist. Take a concrete example. A swimmer does 100m freestyle in 50 seconds. That number, standing alone, is just a data point. But if I know their first 25 meters was 11.2 seconds, their last 25 meters was 13.8 seconds, I understand they are spending too much energy in the start and surface phase. If I know their stroke rate dropped from 48 strokes per minute to 42 in the final 25 meters, I know they are experiencing muscle fatigue and need to improve anaerobic endurance. But in Vietnam, these analyses are rarely done systematically. This leads to a paradox: we have talented swimmers, but we don't know how talented they are, and we don't know what they need to improve to reach continental level. We praise them for SEA Games medals, but we don't ask: why can't their SEA Games results be repeated at ASIAD? Why do they swim faster domestically but slower internationally? The answer lies in the data we don't collect. I had an experience in 2026, when the pandemic canceled all competitions. I spent 8 months archiving data from 2,400 Serie A matches, and I found a market bias: bookmakers often price away teams 5% weaker than reality. In swimming, I believe similar biases exist. We often underestimate swimmers from countries without swimming traditions, and overestimate those from powerhouses. This affects how we invest, how we train, and how we set expectations. Emotion is the most expensive thing in the transfer market. In swimming, emotion is equally expensive. We love stories of swimmers overcoming adversity, of medals won through sweat and tears. But those stories, without a solid data foundation, are just stories. They cannot tell us what to do next. That Saigon summer, I learned that data also needs watering. It needs to be nurtured with patience, with meticulousness, with respect for every small number. A manual xG spreadsheet changed how I view football. A national swimming data system could change how we view an entire sports nation. I'm not saying we should copy the American or Australian model. I'm saying we should start with the basics: recording practice results, analyzing stroke rates, measuring distance per stroke, comparing with regional peers. These data, however crude, will paint a clearer picture of Vietnamese swimming's current state and potential. Football stopped moving, but 2,400 matches still whisper in my spreadsheet. Vietnamese swimming is the same. The numbers are whispering, but we haven't listened. We are still swimming in the dark, proud of medals that could have shone much brighter. Every goal is a data point, but not every data point is a goal. Every medal is the same. It is the result of a process, but it doesn't tell the whole story. Only data can tell the complete story. And that story, I believe, will show us that Vietnamese swimming has so much untapped potential. The question is not whether we have enough talent. The question is whether we have enough data to recognize that talent, and enough wisdom to turn data into results. That is the question I will spend the rest of my career answering.