The Empty Data Sheet and Five Traps of an Athletics Number

The Empty Data Sheet and Five Traps of an Athletics Number

On my desk is a nine-page report. The metric column reads N/A. The comparison column reads N/A. The conclusion column reads insufficient information to assess. No athlete name, no event, no competition date, no source. An empty sheet, perfectly formatted, with room for everything except evidence.

To most readers it is waste paper. To me it is a measurement. An empty sheet does not deny data; it measures how much information the observer actually holds — and in athletics, observers usually hold less than they think.

The day football stopped, I started counting strides again. In 2026, working in the data room of Hai Phong FC, I learned to open every meeting with a number rather than an opinion. Moving into athletics taught me something football never did: some numbers are technically correct and still useless for evaluation. The distance between those two kinds of numbers is usually one line of competition conditions.

Athletics is the only sport that writes conditions into the record

Football does not record the wind speed of a decisive pass. Basketball does not record the humidity of a three-pointer. Athletics records everything: wind speed, altitude above sea level, track name, shoe type, timing method, doping control officer. Those facts belong to the performance on equal footing with the number itself.

World Athletics limits wind speed to 2.0 m/s for records in the 100m, 200m, long jump, triple jump and short hurdling events. Above that threshold the mark still counts for the competition but is removed from record lists. On the road, sole thickness has been capped at 40mm since 2026, after carbon-plated shoes sent marathon records tumbling in two consecutive seasons. On the track, the cap was tightened considerably lower.

Then the clock. A hand time in the 100m is converted by adding 0.24 seconds; in the 200m and 400m, 0.14 seconds. No national record has ever been set with a stopwatch in a hand, at least on paper.

Those three layers of conditions — wind, shoe, clock — are enough to turn a beautiful-looking number into one that cannot be compared. Yet most athletics results in Vietnam reach the public as a single line: name, event, time. No wind. No splits. No equipment note.

A result file usable for analysis needs seven fields: name, event, time, wind speed, timing method, track condition and split data. At many international meets those seven fields are published within hours. At domestic meets, usually only the first three appear.

The SEA Games cycle makes it worse. SEA Games 31 was held in Hanoi in May 2026, SEA Games 32 in Phnom Penh in May 2026, SEA Games 33 in Thailand in December 2026. Each edition produces a short burst of numbers, and most of them arrive without conditions attached. Fans remember the number. Few remember the wind.

I have read hundreds of such sheets. From them I derived five traps, ranked by how much damage they do.

Trap one: wind and altitude

Two athletes who both run 10.10 in the 100m are not at the same level if one faced +1.9 m/s and the other ran into a -0.8 m/s headwind. The maximum wind spread the rules allow can be worth more than a tenth of a second over 100m — enough to reshuffle a SEA Games final.

In the 200m and in jumps the effect is larger, because the athlete spends more time airborne and more time inside the wind zone. A 7.90m long jump in legal wind and an 8.05m jump above the limit can come from the same pair of legs.

Altitude behaves the same way. In Bogota, where the track sits at roughly 2,640m, thin air cuts drag and both sprints and jumps benefit. Vietnam has almost none of that advantage, but it does have wind, especially on coastal tracks or in partially roofed stadiums.

My handling rule is simple: any number not published with its wind speed drops one confidence grade. Not discarded, just flagged. Flagging in the right place beats deleting in the wrong one.

Trap two: the equipment dividend

Carbon-plated shoes, new-generation track surfaces, low-drag suits. When an entire generation gets faster at once, what is being measured may be the equipment. To know which part of an improvement belongs to the legs, you compare the same athlete before and after a shoe change, not one athlete against another.

My test: take an athlete's marks across three seasons before a shoe switch and three seasons after, holding event and racing load constant. If the curve breaks exactly at the switch, most of that jump does not belong to the legs. If the curve rises steadily through both periods, the equipment is a secondary variable.

The same logic works when equipment data is missing. I ask three questions: when did this athlete change shoes, has the track surface been replaced in the last two years, and does the gain match the gain of the control group. If the whole group improved, the story is equipment. If one person improved, it may be a human story.

Trap three: small samples

One explosion is not a level. Across four months in 2026, when football stopped for the pandemic, I re-examined 2,300 matches to build a pressure model combining PPDA, defensive distance and pressing speed. One good match says nothing. Ten start to speak. Thirty allow a conclusion.

In athletics my threshold is five official competitions in a season, same event, same training phase. Below that, the honest description is: once. Do not call once a level of form.

I learned the long-series lesson from someone else's mistake. Before the 2026 World Cup I published an analysis of Germany based on qualifying data: average PPDA of 9.2, slow build-up speed, middling xG. I concluded they would go out in the group stage. Social media mocked me for seeing only numbers. On 27 June 2026 Germany lost 0-2 to South Korea with 26 shots and 1.5 xG. I did not see Germany lose. I saw a number that does not lie.

What I actually took from it was not that I was right. It was that I was right because I had read a ten-match qualifying series, not because I had read one match. With one match, I would have had nothing to say.

Trap four: training marks

A mark set in training has no officials, no doping control, usually no electronic timing and no paperwork. It has value for the athlete and the coach. It has no value for an outside evaluator.

A record becomes a record only after ratification: a licensed competition, a certified track and timing system, doping control, a signed official report, and a submission to the federation. Skip that process and you are comparing a number against a story.

On the roads, two useful reference points are Kelvin Kiptum's 2:00:35 at the Chicago Marathon on 8 October 2026 and Ruth Chepngetich's 2:09:56, also in Chicago, in October 2026. Both are numbers with full conditions and a ratification process attached. That is why they can be argued about seriously.

Trap five: missing split data

This is the most expensive trap in Vietnam. An 800m result does not show whether the athlete ran the first 400m fast or slow. A marathon does not show whether the finish was stronger or weaker than the first half. A runner who paced evenly and a runner who collapsed at 700m can produce the same finishing time, and the two should be read completely differently for next season.

In the 400m hurdles the gap is wider. In the same 55-second race, the athlete who runs 25 seconds for the first 200m and finishes in 30 has good distribution but limited base speed. The athlete who runs 23.5 for the first 200m and fades to 31.5 has good base speed but poor tactics. Training both on the same programme wastes one of them.

In football I hit the same wall with PPDA. A match-average pressing figure cannot separate a team that presses evenly from one that presses only for the first 20 minutes. Split into 15-minute blocks and the picture changes — which is how I found a young midfielder in the Hai Phong academy with an average PPDA of 6.8, the highest in the development system, while he was barely mentioned because of his modest build. I brought that sheet into a meeting and asked for a chance. Against Hanoi FC in round 17 of that V.League season he won the ball 14 times, provided one assist, and the team won 2-1. Without split data he is still on the bench.

Without splits, we are reading athletics with half the data.

Contrarian angle: getting faster together is not getting better together

There is a tempting conclusion: better shoes and faster tracks make records, so every new record deserves suspicion. I leaned that way once and had to correct myself.

Kenyans and Ethiopians have dominated distance running since the 1960s, when shoes were flat pieces of leather. What built that dominance was the depth of the pool, the age-ladder selection system, the density of competition. Carbon plates arrived later, and they did not create a single distance-running nation.

Conversely, some athletics programmes buy the best equipment available and still fail to produce one marathoner under 2:10. The real signal of an athletics nation is how many athletes cross a threshold, not the record of the best one. The peak answers a question about ability. The depth answers a question about the system.

The bigger trap sits elsewhere. We use other people's numbers to draw conclusions about other people. The empty sheet on my desk today does not say any athlete is weak. It says I have no right to conclude. Data is a mirror. Most of the market looks into it and sees only itself.

Hai Phong taught me that the star is not on the shirt, it is in the metrics. But the same city taught me the second half — a metric without its conditions attached is just another shirt, prettier, still fabric.

What to track in the 2026 season

I will track three things, and none of them is a record.

First, whether the national championships publish wind speed and splits. It is the cheapest possible intervention and it creates the most value for every analysis downstream. A seven-field result file instead of a three-field one needs no new machinery, only one extra column in the official report.

Second, the number of athletes under 20 hitting specific time marks over 100m, 200m and 400m within a season. That number measures the system, not the individual. It is also the hardest figure to fake, because producing many athletes above a threshold takes many years of correct development.

Third, injury-return seasons. Injuries are random; calendars are not, and how an athlete returns after eight months out is more reliable data on the professionalism of an entire team than a medal. An athlete back at the same event and the same marks after a serious injury says more than silverware.

While the football transfer market lives on rumour, athletics still lives on official reports. An empty data sheet can still be filled. My job is not to fill it with guesses.