Vietnam Women's Volleyball and the Data That Was Never Recorded

In my tracking notebook there is one page left blank. It sits between two densely written pages, every line a symbol I devised myself after years in the stands: the libero's starting position, the direction of the opponent's serve, the gap the block left open after each run. That blank page belongs to a set played by the Vietnam women's national volleyball team. I tried to log every rally as I do for any other match. Then I stopped, because I understood I had no way to verify what I had written, and no data source to cross-check it against. Two hundred and four rallies. I counted them. The score of each set, the names of the scorers, a few successful blocks, a few service errors — all of it is in the notebook. But the team's perfect-pass rate in that set, I left blank. The number of out-of-system attacks, I left blank. The number of times the block touched the ball before it fell on our side, I left blank too. Not out of laziness. Because those metrics, in Vietnamese women's volleyball, do not exist in a public and cross-checkable form. That blank page is why I am writing this. Vietnamese women's volleyball is living through the most noticed period since I began following the sport. National team matches are broadcast live, with commentary, with on-screen graphics, with thousands of comments scrolling beneath the picture. Tournaments such as the VTV Cup, the SEA V League and the various editions of the AVC Challenge Cup draw crowds into the arena and onto screens at a frequency nobody would have imagined ten years ago. The national championship has sponsors, broadcast contracts, and matches that sell tickets. Alongside that, a generation of Vietnamese players has stepped beyond the border. Tran Thi Thanh Thuy went to play in Japan's V.League from the 2026 season in the colours of PFU BlueCats, according to information released by the club. Other names have found places in regional leagues. These are signs of a sport on the rise, and they make me want to do my own part properly. The information infrastructure, however, has not grown at that pace. At most domestic matches, the only officially published output is the score and the list of scorers. There is no point-distribution table by rally, no perfect-pass rate, no rotation-level data. A coach who wants to know what percentage his player passed at in the fourth rotation of the third set has to pay someone out of his own pocket to sit and count. A journalist who wants to verify a tactical claim has to reconstruct the match by eye. Elsewhere in the world the picture is different. FIVB operates an official statistics system for world-level events in which every rally is coded and tagged. Major national leagues in Europe and Asia hire dedicated data crews to record each ball, using analysis software that is standard in coaching circles. In Japan, where Thanh Thuy plays, every match leaves behind a public data sheet after the final whistle, detailed enough that fans argue with numbers rather than feelings. That gap is not about technology. It is about whether data is treated as part of the competitive product. I want to explain why the missing metrics matter so much, using the sport's own language. The first metric is the perfect-pass rate. In volleyball, the first ball after the opponent's serve determines almost everything that follows. A perfect pass puts the ball in exactly the right spot for the setter to run the full tactical menu: the quick middle, the quick to the pin, the back slide, the high ball outside, the ball behind the setter. A poor pass allows the setter only to push the ball to the wing and let someone improvise. On screen the two situations can look identical: still an attack, still possibly a point. But they belong to two different structural worlds. For a squad shorter than its opponents in average height — the long-standing reality of Vietnamese women's volleyball against the continent's leading teams — the ability to hold a high perfect-pass rate is a survival mechanism. Fast play is how you compensate for height. Fast play only exists when the first ball lands in the right place. If nobody records that rate, we will keep arguing by feel about whether the team passed well or badly. I have sat in press rooms many times and heard the sentence "the passing was poor today". That claim may be correct. But it cannot be verified, cannot be compared across matches, and cannot be used in training. The second metric is the number of out-of-system attacks. These are rallies in which the team must attack with an imperfect second contact, the ball outside tactical control. At professional level, the out-of-system share reveals the burden placed on individuals. A team with a consistently high share is depending on individual problem-solving rather than on a system. This is especially relevant to Vietnam's women's team. Tran Thi Thanh Thuy and Nguyen Thi Bich Tuyen are the two main attackers handed most of the difficult balls. Looking at the score sheet, people see high point totals and conclude they played well. Looking at an out-of-system distribution, people would see a different story: the system is pushing too many hard balls toward them, and that only looks fine while they still have the legs for it. I do not have official data to prove what that share is. That is exactly the problem I am describing. A volleyball nation that wants to go further needs to know how much it leans on individuals, and the out-of-system metric is the most direct gauge. The third metric is block touches. In volleyball, a successful block appears clearly on the score sheet. But a block that only grazes the ball, slowing it enough for the back-court defence to pick it up, appears nowhere. Those blocks are invisible contributions. Hoang Thi Kieu Trinh and Le Thanh Thuy, who regularly stand at the middle of the net, may hold a defensive value far greater than the raw block totals in a simplified stat line suggest. A block that merely touches the ball also changes its direction, forces the opponent to rebuild the attack, and buys the defence time to organise. Without this metric, we are grading blocks on half the truth. The fourth metric is the ratio between direct service points and service errors. In women's volleyball, serving is a strategic weapon, particularly against teams with stronger attacks. A serve powerful enough to break the opponent's reception system is worth nearly as much as a direct point, even when the ball is still dug up. But if only direct service points are recorded, we will undervalue players who serve tactically to disrupt rather than to score. Conversely, a player with three aces and twelve service errors is hurting her team. A simple score sheet cannot distinguish these two cases. This is the kind of information a full data sheet resolves in seconds. The fifth metric, and perhaps the most neglected, is rotation-level data. Volleyball divides a match into six rotations, each with a different attacking and defensive structure. A rotation with only two front-row attackers is a theoretically inherent weak point. A coach can cover that weakness by placing the libero correctly, by choosing the right server, or by accepting the trade-off. Without rotation data, every decision of this kind rests on experience and memory. The experience and memory of good coaches are real assets. But they cannot be passed on, cannot be verified, and cannot be improved systematically across seasons. I built my own tracking sheet. The method is entirely manual: split the screen, and for each rally record the server, the first contact, the quality of the second ball, the final attacker and the outcome. One set takes about two hours to log, and I have to rewatch the footage at least three times for the fast rallies. With that method, I can cover one team in one match per week. Based on my experience tracking matches over several recent seasons, a fairly clear pattern repeats when the Vietnamese women's team faces opponents with a height advantage. It is what I call a chain collapse: when the perfect-pass rate falls in two consecutive rotations, out-of-system attacks spike in the following rotation, and lost points tend to arrive in runs of three or four rather than scattered. A run of conceded points is the signature of a systemic problem, not of one player hitting out. With data, we could point to exactly which rotation is the breaking point, and a coach could prepare a substitution for that precise spot. Without data, everything happens in silence and gets explained with the word "psychology". I want to spend the final part on what troubles me most, and it is not a technical matter. There is a common assumption that missing data is a matter of missing money. I do not think so. The cost of hiring a basic stats crew for one match is no greater than the cost of staging an opening ceremony or a press conference with a branded backdrop. The issue is that data does not appear on the list of things considered worth paying for. The commercial value and the competitive value of data travel along two different roads. Tournament organisers care about image, viewership and sponsorship contracts. A perfect-pass table sells no extra tickets. Media care about stories, emotion and viral moments. A rotation distribution table creates no viral moment. Only two groups genuinely need detailed data: coaching staffs and analysts. Neither group pays for the data system. That is why the structure keeps this gap alive for years without anyone having an incentive to fill it. On the other hand, I do not believe that simply having more numbers automatically produces better analysis. A data table without context creates what I call pseudo-data: figures that look precise but lead to wrong conclusions, because they are read without accounting for opponent quality, playing conditions or a player's physical state. A textbook example is the weak-opponent trap. A team that passes beautifully against gentle servers will show a lovely perfect-pass rate on the stat sheet. That number collapses the moment it meets a heavy-serving side. If the analyst does not adjust for opponent strength, they are measuring the wrong thing. There is one more issue the profession argues about a lot: how to define a perfect pass. One view holds that only balls arriving exactly at the setter's position count. A broader view includes balls landing within an acceptable radius of that spot. The two definitions produce very different rates from the same match. The point is not which one is right. The point is that no unified standard has been published and applied consistently across Vietnamese women's volleyball. When no standard exists, every number can be argued into irrelevance. Meanwhile, I keep doing my manual work. And I have noticed something interesting: precisely because I have to count by hand, I notice details that an automated stat sheet might swallow. For instance, the way Nguyen Thi Kim Lien moves before the serve is struck. The libero stands offset to one side, and the direction of that offset often predicts where the opponent will serve. When she stands centred in a low stance, it signals a set in which the team accepts playing high balls. Details like these cannot replace data. But if the data existed, they would be the explanation attached to the numbers, rather than something the numbers erase. What encourages me is that some changes are happening slowly but genuinely. Youth clubs have begun filming entire matches instead of only cutting highlight reels. A few young coaches are now used to asking assistants to log point distribution by rotation. Tournaments streamed online leave behind footage that can be reviewed, and that is the first material condition for any data system to be born. But material conditions are not enough. What is still missing is a decision: to treat data as a mandatory part of a professional match, like the referee, like the net, like the scoreboard. I think about the blank page in my notebook. If one day the perfect-pass rate of the Vietnam women's national team is published after every match, alongside out-of-system attack counts and point distribution by rotation, I will no longer have to leave any page blank. And at that point, the argument about the national team will shift from who is good and who is not, to what the system is doing, which rotation needs fixing, and where a substitution should be made. That is a harder argument. But it is the argument Vietnamese women's volleyball is now big enough to start.