The Blank Field on the Scouting Sheet: Vietnamese Youth Table Tennis and Its Data Thirst

Late August, I sat at the edge of an indoor hall in a provincial sports centre, behind me the row of table seven, where a fourteen-year-old boy was practising his serve. His name was Khoi, left-handed, with a hard Chinese-style rubber on the forehand and a soft Japanese-style rubber on the backhand. The blade already told a story about the boy holding it: a spin-oriented game, not a flat-hitting one. For forty minutes, Khoi repeated one single motion — high toss, short backspin into the left corner, then turning to wait for the return. His coach sat beside me, holding a pre-printed scouting sheet. I glanced at it: almost every field was blank.

It was not laziness. He told me something I carried with me for weeks: "What am I supposed to write, teacher? He hits three hundred serves a session, but where do I get the numbers?" That question belonged to more than one sheet of paper. It belonged to an entire system that runs on the human eye and has not yet learned to run on data.

What I saw that afternoon was a familiar paradox of Vietnamese youth table tennis. At the professional scouting level elsewhere, a fourteen-year-old can be described by dozens of metrics: spin rate measured in revolutions per minute, point-win rate on serve, attack-win rate on the second receive, footwork trajectories across three steps, the number of transitions from backhand to forehand within a game. At the same age here, a file usually contains three lines: name, year of birth, tournaments played. The rest is entrusted to the intuition of someone sitting outside the court.

I do not dismiss intuition. For ten years I have travelled to the grassroots with intuition and a notebook. But intuition cannot be shared. It does not travel from a provincial coach to a national training centre, nor from one generation to the next. A blank sheet is not proof that a child has nothing to measure; it is proof that we have not yet built the ruler.

There are seedlings that do not need the big stadium lights, only a patch of warm enough soil to take root. But warm soil is no substitute for water. For years, our youth table tennis has lived on the memory of players who reached the national team thanks to the eye of a few teachers. That approach worked, and I will not deny it. But it carries one fatal blind spot: if that teacher retires or moves on, the accumulated knowledge vanishes with him.

I have witnessed that. In 2026, I followed a talent class in central Vietnam. Its head coach kept a thick notebook, hand-recording every session of every child over seven years. That notebook was the centre's most valuable asset. Then he was transferred. The notebook stayed in a drawer, and no one could read it again, because his handwriting was a scrawl and his symbols were his own.

That is when I understood why data matters. Data is not there to replace the eye, but to preserve what the eye saw once the eye is no longer in the room.

Apply a technical-analysis framework to Khoi's case and you hit the first void immediately. What is his technical system? Two-winged looping, backhand flat hitting, or controlled blocking? No one recorded it. What percentage of his serves in a match are short backspin? No one counted. How many revolutions per minute does his forehand loop generate? No one measured, because the centre owns no spin-measuring device. And his blade, that hard-soft rubber pairing — was it chosen to amplify a strength or to mask a weakness? No one can answer, not even the person who glued it.

This is the kind of void that renders every downstream analysis meaningless. One can build a beautiful table with sections labelled "technique", "tactics", "physicality", and fill them with vague remarks such as "has potential" or "needs mental work". But those sentences have no predictive value. They cannot distinguish a boy who will become a national-class player from one who will stop at the qualifying rounds of the national youth championship at seventeen.

The second void is head-to-head data. Table tennis is a sport where results depend enormously on the specific pairing. A player can beat one opponent three sets to nil and lose four straight to another, purely because the spins do not match up. In professional systems, head-to-head history is stored and classified by opponent type: left-hander versus right-hander, pimpled versus smooth rubber, away-from-table versus close-to-table. Here, that history does not exist in any searchable form. It lives in a few memories, and memory is selective.

The third void belongs to the tournament system. Vietnamese youth table tennis plays far too little. If a fifteen-year-old enters three events a year, a few matches each, the total number of matches you can record about him in a full year is under twenty. With twenty matches you can tell a story, but you cannot conclude anything about true ability. A win rate over twenty matches is far less certain than a win rate over two hundred.

And here I want to pause longer, because this is the heart of the data problem: the smaller the sample, the more easily a story is distorted into a legend. One beautiful win over a strong opponent can create the belief that this child is the future of an entire generation. One heavy loss can remove him from every list. Both judgements rest on a single observation, when the nature of table tennis is volatility.

I saw both extremes within the same week. In the morning, a coach told me about a thirteen-year-old: "This one will make the national team, I am sure." In the afternoon, that same boy lost a group-stage match, and another person said: "He is too raw, there is nothing there." Both spoke with certainty, and both had nothing but one match.

I do not write about today's match, but about the person they become afterwards. Judgements based on a single match are not prophecy; they are gambling.

At the governance level, I once heard a proposal to create a shared youth table tennis database. The idea died young for three very Vietnamese reasons. First, no one was responsible for entering data regularly, because that work earns no medals. Second, the centres did not want to share information about their trainees, for fear of having talent "poached". Third, and this is the deepest reason, we have not yet formed the habit of treating data as an asset.

This leads to a consequence I call double risk. Without data, we risk both dropping good talent and keeping for too long players who no longer have growth potential. Both mistakes are costly, but the cost runs in different directions. Dropping talent loses an opportunity. Keeping too long burns money on a road that has already ended.

Every generation of talent is a geological layer; dig the wrong stratum and you pick up rubble. And to know which layer you are digging, you need a map. That map is data. Without it, the scout can only dig blindly.

Now I want to touch something that seems to run against the grain of this piece. The blank sheet I held that afternoon was not an unmitigated disaster. It was honest. A blank sheet tells the reader: "Here, we do not yet know." A sheet filled with unfounded remarks is far more dangerous, because it creates the illusion of understanding.

I have seen such sheets. They read: "Good energy, long-term development, needs physical improvement." Those sentences sound reasonable, sound professional, and cannot be verified. If behind them there were a concrete metric — average distance covered per game, win rate in the fifth set, number of serves attacked in the first ten rallies of a set — the next coach could use it. Without metrics, those sentences merely decorate a file.

So my counter-intuitive conclusion is this: the problem for Vietnamese youth table tennis in the coming phase is not a shortage of good analysts, but a shortage of recorders. One person sitting outside the court, noting every point, every serve, every misplaced foot, without judging, without concluding, just recording. A year later, that store of data will say things that ten experts guessing could never match.

Some argue Vietnam lacks the resources for such work. I do not entirely disagree. We cannot equip every provincial centre with spin-measuring machines, nor pay hundreds of data recorders. But modesty has many grades. At the lowest grade, we can agree on one standard recording sheet nationwide and require every youth event to use it. No high technology needed. Just a common template, a common naming method, and a rule that no tournament ends without submitting its data.

I tested this at a small youth event in June. A group of coaches voluntarily shared a simple recording sheet: each player had a code, each match recorded set-by-set scores, serve faults, and points won while leading by two. That was all. At the end of the event they discovered three things the naked eye could not see: one player had a surprisingly high fifth-set win rate, another collapsed completely once trailing, and one pairing had a far higher reversal probability than general perception suggested.

Those three findings needed no machinery. They needed consistency. And consistency is something we can build by resolution, without a large budget.

I understand why many in the industry hesitate. Data forces people to confront what contradicts their feelings. It may say that the child you love is not progressing as fast as you thought. It may say that the style you believe in is being decoded by opponents. Facing that hurts far more than continuing to trust intuition.

But table tennis is a sport where the gap at the top is measured in milliseconds and spin revolutions. The human eye, however sharp, cannot measure that gap. The ball crosses the table in about a quarter of a second. No one has time to analyse in that window. Every decision is made before the ball arrives, based on habits formed over thousands of hours of practice. To improve those habits, you must know where they go wrong. To know where they go wrong, you need data about them.

Speed and silence each have their own language; I merely write them down. The blank fields on that coach's sheet had their own language too. They did not say Khoi has no future. They said we do not yet know, and if we keep not knowing, we will judge the boy by feeling.

Saigon is entering its rainy season. The national youth tournaments are about to begin. Sheets will be printed again, and many fields will be left blank again. What I hope for is not that every field is filled within a single season. What I hope is that at least one person, in some province, decides to keep those sheets instead of throwing them away when the tournament ends. A year later, that person will possess something no one else in the industry has: a geological layer left undisturbed.