When the Spreadsheet Returns Zero: The Discipline of Badminton Analysis in Vietnam

I opened the data file at 23:40 Surabaya time and got back a blank frame. It should have contained more than four hundred rows from a men's singles match at an international badminton tournament held in Vietnam: rally length, serve landing point, the player who made the final contact, and the court zone where each point ended. What I received was a row of column headers and empty space beneath them. The organiser's statistician stopped recording after day two because there was nobody left on shift, and the remaining three days of the tournament vanished from history as numbers.

I sat still in front of the screen for a long while. My job is to turn movement into digits, but in that moment the only thing I still held was the memory of a sweltering afternoon inside the hall, the squeak of shoes on the mat, and the sense that the player on the left side was losing hip rotation in the third game. That sense has no column to be typed into. Numbers are the prayer book, but intuition is the candle — I light both whenever I read a match.

This story does not begin with a corrupted file. It begins with the large part of Vietnamese badminton that operates without any data net underneath it.

Context: a sport run by hand and by eye

I work as a data consultant for a football club in Surabaya, but my badminton tracking spans events inside the BWF system down to small international tournaments staged in Vietnam and Indonesia. The infrastructure gap between those two ends is far wider than the gap in playing level.

At the top tier, badminton has entered an era of automated measurement: camera tracking of shuttle landing points, shuttle speed data, rally packages repackaged and sold to broadcasters. At the lower tiers, where most Vietnamese players spend their careers, everything is still recorded with a pen. People write down the score. Sometimes they write down match duration. Rarely do they write down why the score moved the way it did.

That gap is not merely technical. It decides who gets seen. A player who wins 21-19, 21-18 by picking the right moment to advance to the net leaves exactly the same trace as a player who wins on two lucky net cords at the death. The scoreboard is fair about outcomes and blind about causes.

In 2026, while working as a data consultant for a Liga 2 club in Indonesia, I advised the coach to push the defensive line higher in the promotion play-off based on an expected-goals model that projected 1.8 goals. We lost 0-2, and every attempt was a harmless shot from outside the box against a deep block. I had ignored PPDA and shot origin. The model was not wrong; I was wrong to make it speak instead of my own eyes. That lesson followed me into badminton and shaped how I handle empty datasets: eyes first, model second.

At the 2026 World Cup, Croatia did not win the trophy. But their group-stage PPDA of 9.2 and the tournament's highest rate of ball recoveries in the opponent's half revealed something the results table could not: pressing timing is a skill, not a tactic. Croatia did not win, but they showed me a truth hidden inside a number. For Vietnamese badminton, a comparable truth still has no name, because nobody has committed to writing it down.

Core: three layers of reconstruction when the spreadsheet returns zero

When data is absent, I do not stop analysing. I change the raw material.

The video layer. One camera placed high behind the court is enough. I code four variables for every rally: number of contacts, the shot that ended the rally, the shot immediately before it, and the losing player's position at the moment the opponent struck. Four variables, no more, on the first viewing. My experience is that coding six or seven at once inflates the error rate beyond the informational value gained, and the homemade dataset becomes an unreliable witness.

The spatial layer. The court is divided into twelve zones: three vertical bands (net, mid-court, rear court) multiplied by four lateral lanes (two tramlines and two central lanes). For each rally I record the starting zone and the finishing zone of each player. After roughly two hundred rallies, a hand-drawn heat map emerges, and it usually tells the story the score refuses to tell: the neglected space in the rear cross-court corner, or the tendency to retreat too early after a net shot. A player's true value lies where he runs and when he stops.

The context layer. This is the most neglected layer and the one I paid a price to learn. Schedule density, flight hours, hall humidity, the batch of shuttles in use, the direction of the air conditioning. In 2026, when the pandemic halted competition, my model built on fifteen opening rounds collapsed once football resumed: my team lost three straight matches because opponents pressed harder in empty stadiums. The variables "crowd" and "distance between lines without noise" sat in no column of mine. The pandemic taught me that data can be afraid too — when the world stops, numbers become meaningless.

Those three layers are enough to build the metrics I find most useful for badminton at events with no automated measurement.

Cross-court success under pressure counts only rallies in which the player had already been pushed off the central position and was forced to strike while off balance. It measures technical nerve in the worst state, which is nothing like overall rally win rate.

Net-shot frequency in the third game is a simultaneous indicator of fitness and psychology. In the decider, once the legs are heavy, a rise in net-shot attempts usually comes from one of two opposite causes: the player wants to shorten rallies because he is out of gas, or he is confident and actively dragging the opponent forward. Video distinguishes the two. The scoreboard cannot.

Excess movement in a lost game counts steps between two strokes and compares them with the minimum distance required to recover to the central base. The difference is the price of reading the match late. A 17-21 loss with high excess movement tells a very different story from a loss by the same score with low excess movement; the first is a positioning problem, the second a stroke-quality problem.

The neglected-space index records, for every stroke, which opponent zone was most open, then compares it with the zone the player actually chose. The gap between "should have played" and "did play" is a measure of tactical thinking, and it never appears on the electronic board.

From these metrics I see a structural difference between the two badminton nations I follow side by side. Indonesia runs a centralised national training camp with a closed system of measurement and conditioning; there, the success number tends to be defined by gold medals. Vietnam is more distributed, with strength spread across provincial training centres, and success is often defined by consistent presence at major events. That difference does not say which side is stronger; it says each is optimising for a different kind of number. One optimises for the peak and one for the breadth, and how each chooses what to record reflects that choice precisely.

The players carrying those two systems — Nguyen Thuy Linh and Le Duc Phat for Vietnam, Jonatan Christie, Anthony Sinisuka Ginting and Gregoria Mariska Tunjung for Indonesia — are products of very different recording cultures. What strikes me is that when I watch their footage through the four hand-built metrics above, the gap narrows considerably. The difference is not made by a federation's data infrastructure. It is made by the quality of decisions in the thousandths of a second that no automated system captures in full.

Based on my experience watching matches inside Vietnamese halls and at regional international events, most fans judge a player by three numbers: the score, the ranking, and the title count. All three are aggregate metrics, and all three rest on a tiny sample compared with the actual volume of movement in a career.

The contrarian angle: a data gap is not neutral

There is an unspoken assumption in how we talk about sports statistics, that without numbers there is no opinion. Reality works the other way. When data falls silent, what fills the vacuum is hearsay, reputation and collective memory. And those tend to favour the already famous.

A young provincial player who has never been fully filmed enters qualifying with an empty file, while a player whose name has been on television enters with a thick one. Neither has genuine technical data, but only one of them benefits from the absence. Data gaps are not distributed fairly.

Even at the technology tier, the problem only migrates rather than disappearing. Instant-review line-call technology exists at a handful of major events; where it does not, the argument does not shrink, it moves to the chair umpire and the desk. The mechanism mirrors what I observe in football with VAR: a new tool does not erase dispute, it relocates dispute into the grey zone of the rulebook and the review room. In badminton, that grey zone is tight line calls, service faults, and situations only someone seated at the right angle can see.

A larger risk sits on the market side. When a sport's data infrastructure is thin, the markets that feed off it start pricing things nobody can verify. Esports walked this road a few steps ahead of badminton: betting grew faster than the capacity to police competitive integrity. For badminton, the exposure lies in the lower tiers, where there is no camera, no oversight, and no history to cross-check. Once public opinion turns toward doubting results, the only foundation available to defend an athlete is a sufficiently thick data archive — something most systems today do not have.

My own limit sits here too. I once wrote a tactical recommendation based on fifteen rounds of an interrupted season, and I was wrong. If I let a data shortage become a licence to speculate, I will repeat exactly that mistake in another sport. The boundary between analysis and invention lies in whether the writer dares to state plainly what is missing.

A forward-looking reflection

The signal worth tracking in the coming period is not a new metric. It sits in process: who records, for how long, and whether the archive survives the season. A federation may not own an expensive camera system, but it can still maintain a continuous manual record across years — and that continuity is worth more than sophistication.

The players who deserve to be seen are usually not the ones with the prettiest scorecards. They are the ones making the right decision at the moment nobody bothers to record. If a badminton nation chooses to record those moments seriously, the first thing to change will not be the ranking table. It will be how we choose whom to place our trust in.

And if I open another empty data file at 23:40, the question I want to ask is not who won the match. I want to ask who agreed to sit down and record it.