Blank Columns in the Notebook: Vietnamese Badminton Is Missing Both Sensors and Digital Memory

Nguyen Du Sports Hall, District 1, one mid-September afternoon. Outside, 34 degrees Celsius, 78 percent humidity, Saigon heat clinging to the skin like an unwrung wet cloth. Inside, the cooling system worked at full power, yet heat still rose from the wooden floor and from two thousand spectators filling the stands. My notebook had three columns: the player's footwork frequency, the distance covered in a game, and the shuttle speed across the net. After two games of a men's singles quarterfinal, all three columns were still blank. The inertial sensor I had strapped onto a nineteen-year-old player spat out garbled data, and nobody on the organizing committee had ever required any metric to be recorded at all.

Three weeks earlier, I had rewatched a tape of a national athletics final. Everything there had a number: splits for every lap, average speed per two hundred meters, heart-rate recovery after the finish line. A runner covering 42.195 km cannot hide anything. A Vietnamese badminton player can hide everything.

To understand why those three blank columns matter more than a second-round defeat, look back at the arc of this sport over two decades. In September 2026, Nguyen Tien Minh rose to world No. 5, the highest mark any Vietnamese player has ever touched on the Badminton World Federation rankings. He competed at three consecutive Olympics: Beijing 2026, London 2026, Rio 2026. The next generation, Nguyen Thuy Linh, Le Duc Phat and Vu Thi Trang, stepped onto the international stage in turn, and Thuy Linh appeared at both Tokyo 2026 and Paris 2026.

At tournament level, Vietnam has the Vietnam Open within the BWF World Tour at Super 100 tier, the Vietnam International Challenge, a national championship, and a dense grassroots circuit from Hanoi to Can Tho. The number of badminton courts in major cities grows every year. On a weekend evening, a district-level hall can serve several hundred players. Badminton in Vietnam is a small, smoothly running economy of court fees, shuttle costs, coaching fees and amateur prize money.

Yet at the measurement layer, the sport is nearly blank. No database records how far a player moves in a game. Nobody logs the average shuttle speed in a rally lasting thirty seconds. Nobody stores the hall's temperature and humidity alongside match results, even though those very numbers determine which shuttle grade is brought onto court. As the regular season rolls past, coaching staffs keep memories, not data.

Vietnamese athletics moved ahead on this front long ago, so quietly that few noticed. A 400-meter race has electronic timing to one hundredth of a second and a slow-motion camera at the start to catch false starts. Swimming pools have electronic touchpads at the wall, recording every 50-meter segment. Those numbers exist even when nobody watches, even when nobody needs them. Vietnamese badminton measures with the human eye, and the human eye retains nothing once the hall lights go out.

A blank data column is not a neutral gap. It is a decision, someone made that decision, and someone benefits from that column never being filled.

Start with the easiest thing to measure: the rally. Current competition laws allow a 60-second interval when a side reaches 11 points and a 120-second interval between games. Those pauses exist so players can recover, but they are also traces of how much stamina has been burned. Yet at a national-level match, I had to count by hand and write in my notebook: average rally length in the first game was 8.4 shots, dropping to 5.1 in the second game, while total match time actually rose by six minutes. That number told me something the naked eye cannot distinguish: the player did not win by hitting longer, he won by shortening rallies and pinning his opponent to the floor.

Nobody recorded that in any official document. Which means nobody can argue against it, nobody can verify it, and nobody can use it to select someone else.

The second column is movement. A singles court has six corners a player must protect, and each rally forces several changes of direction. In one quarterfinal where I rigged an inertial sensor network for a player, we captured 4.2 changes of direction per second at peak load, with footwork frequency reaching 4.6 steps per second across three left-side retrieval situations. Those figures are comparable with any player in the world, if we bother to measure. But they existed only on a laptop beside a banh mi and an iced milk coffee, and they will vanish when the hard drive fails.

When the sensor says what the scout's eye cannot see, I understand why that summer exploded.

The third column is environment, and this is where I get most frustrated. Shuttles are graded by weight in grains, commonly 75, 76, 77, 78 and 79. The higher the number, the heavier and slower the shuttle flies. Choosing a grade depends directly on hall temperature and humidity, and in some venues also on altitude above sea level, since thinner air makes shuttles fly noticeably faster. Every tournament makes a shuttle-choice decision, but that decision is almost never recorded alongside match results.

I once logged an afternoon in Saigon with humidity above 80 percent: a slick court, slow shuttles, longer rallies, and a clear drop in jump count for both players after the middle of the second game. If a dataset captured temperature, humidity and shuttle grade for every competition day across a season, we would know which players adapt well to Saigon's climate and which only perform in Hanoi in November. The national team is missing exactly that table.

The fourth column is recovery. In athletics, I know how long a 1500-meter runner takes for heart rate to return to resting level, and that figure decides the finishing kick tactic. In badminton, heart-rate recovery between rallies is barely recorded in Vietnam. The laws allow a 60-second interval at 11 points, meaning organizers already acknowledge a physiological threshold exists. We simply have not bothered to measure it.

The fifth column is the crowd, which I have always believed is the most undervalued data of all. In 2026, when halls closed, I phoned twelve athletes in self-isolation, including one runner who covered a full 42.195 km around his balcony. He said the feeling of competition disappeared after just four days without the sound of people. The empty hall of 2026 did not kill badminton, it merely exposed that this sport never developed the habit of recording itself. A player who performs well before two thousand spectators and poorly before two hundred is two different athletes. We have no data to prove it, so we settle for a vague word: mentality.

The consequence of those five blank columns funnels into one place: talent identification. In Vietnam, the decision to call a player up to the national team usually rests on two things, head-to-head record and the impression of onlookers. Head-to-head record is a crude, honest number, but it says nothing about how a player wins. Impression is something that cannot be refuted, because there is nothing with which to refute it. The word "form" in technical meetings thereby becomes a word of power: unmeasurable, therefore unfalsifiable.

I was in that room once, in June 2026, when a Saigon club invited me to test inertial sensors on a nineteen-year-old newcomer. He ran the flank with a footwork frequency of 4.8 steps per second, 0.2 meters longer than the sprint standard I was used to measuring on the track. I built a video comparing his running mechanics with a 400-meter athlete and was criticized by traditional coaches for turning football into athletics. But the data stayed there, and three years later, when he broke out, nobody mentioned my notebook again.

In other sports, this story was settled long ago. Nguyen Thi Oanh won three gold medals at SEA Games 31 on home soil in Hanoi, and each medal came with a detailed splits table down to the lap. Nguyen Huy Hoang took silver at the 2026 Asian Games in the 1500-meter freestyle, a result recorded to one hundredth of a second. Bui Thi Thu Thao won long jump gold at the 2026 Asian Games with a decisive jump measured to the centimeter. Nobody can argue with those numbers, not even people who dislike the outcome.

Vietnamese badminton is still arguing with memory. Measuring a badminton player with the ruler of a track athlete, I see that talent never waits for the stopwatch, but talent also cannot survive if nobody bothers to press it.

At this point, one thing must be said plainly, and many will not like it: a lack of money does not explain the whole story. A mid-range smartphone has enough accelerometer and gyroscope capacity to measure footwork frequency within acceptable error. A free timing app is enough to log rally length. A thermometer and hygrometer hanging in the corner of a hall cost less than a tube of shuttles. The barrier lies in the habit of asking questions, and in the fact that nobody is held accountable when those questions go unanswered.

More dangerously, when data finally arrives, it is easily misused. In this industry, statistics are often brought out to rationalize a decision already made, not to overturn it. A coach who has already picked a lineup will find a few metrics to prove himself right and ignore the rest. Using data that way is more dangerous than having none, because it drapes a scientific coat over subjective judgment.

Conversely, I do not want to sit in the sensor-worshipping camp either. A fully populated data column can still lead to a wrong conclusion if the person reading it does not understand the sport. The 2026 episode is a two-sided example: the sensor saw a quality the scout's eye missed, but the sensor could not say what to do with that quality. Instruments measure; they never decide for people.

I do not write to glorify anyone, I write to expose the next mistake. And the next mistake of Vietnamese badminton will not be a single overlooked player, it will be an entire generation overlooked because nothing was ever recorded about them.

There is one question I have not answered in thirty-four years of holding a pen: who really benefits when those columns stay blank? Whoever answers that question will rewrite how we select athletes.

The first person to keep a proper notebook through an entire season, filling all five columns, will accomplish something nobody has in thirty-four years: giving Vietnamese badminton a memory that can be verified. After that, when debates erupt, people will have to speak in numbers rather than in reputation. That debate will be far more uncomfortable than what is happening now, and I believe we have been ready for it for a long time.