Verificando nosso trabalho

As probabilidades se confirmam?

Quando o modelo diz que uma seleção tem 70% de chance, essa seleção deveria vencer cerca de sete em cada dez vezes. Esta página verifica se isso acontece. Cada jogo da Copa do Mundo 2026 é avaliado no momento em que é disputado, e os números abaixo fazem uma pergunta: as probabilidades são honestas, não apenas confiantes? (O nome técnico para isso é calibração.)

Track record

Proven on past tournaments

The short version: when the model says 70%, it happens about 70%. Across these 987 matches its stated chances landed within ~5.6 points of reality, and on average it rated the actual result about 35% more likely than a blind 1-in-3 guess would.

The 2026 tracker below stays empty until the first match kicks off. So to show the model has been tested, not just described, we ran it against tournaments whose results you already know. For each one, the model was rebuilt exactly as it stood the day before kickoff, then graded on every match — it never sees the result it is being marked on. That is what “graded out of sample” means: no peeking, no hindsight.

Each tournament is scored by the production model reconstructed as it stood the day before the tournament's first match: Dixon-Coles and Hierarchical Poisson refit on matches strictly beforehand, Elo rolled forward to each match, and the tournament-tier calibration layer refit on the 24 months of matches before the cutoff. No data from the tournament, or any later match, touches any layer of the fit.

Graded across 987 matches at 24 major tournaments (2014–2024)

0.572

How close the forecasts landed to reality. Lower is better; blind 1-in-3 guessing scores ≈ 0.667.

1.000

Like Brier, but overconfidence is punished harder. Lower is better; blind guessing scores ≈ 1.099.

5.6pp

Does “70%” really mean 70%? The average gap between the two. Lower is better.

Tournament by tournament

One row per tournament: the model rebuilt as it stood the day before it began, then graded on every match through the final (Brier — lower is better, blind 1-in-3 guessing is 0.667). A few thin, early editions sit above that line; the honest measure is all of them pooled, in the box above.

TournamentHostMatchesBrier
Copa América 2024United States320.522
Euro 2024Germany510.613
AFCON 2024Ivory Coast520.651
Asian Cup 2024Qatar510.515
Gold Cup 2023United States310.566
World Cup 2022Qatar640.611
AFCON 2022Cameroon520.686
Gold Cup 2021United States310.341
Copa América 2021Brazil280.481
Euro 2021England510.554
AFCON 2019Egypt520.546
Gold Cup 2019United States310.405
Copa América 2019Brazil260.542
Asian Cup 2019United Arab Emirates510.496
World Cup 2018Russia640.569
Gold Cup 2017United States250.456
AFCON 2017Gabon320.642
Euro 2016France510.668
Copa América 2016United States320.502
Gold Cup 2015United States260.755
Copa América 2015Chile260.686
AFCON 2015Equatorial Guinea320.795
Asian Cup 2015Australia320.434
World Cup 2014Brazil640.565

Reliability diagram

Read it like this: each dot is a group of similar forecasts — left-to-right is what the model predicted, bottom-to-top is how often it actually happened. When the model says 70% and that happens about 70% of the time, the dot sits on the dashed line: perfect calibration. The closer the dots hug the line, the more honest the probabilities; bigger dots mean more matches in that group.

Reliability diagramReliability diagram: predicted probability on the x-axis, observed frequency on the y-axis, binned in deciles across [0, 1]. Closer to the identity line means better-calibrated.0.000.250.500.751.000.000.250.500.751.00n=327n=478n=911n=329n=269n=217n=184n=134n=73n=39predicted probabilityobserved frequency

Brier by favourite confidence

Matches grouped by how confident the model's favourite was (its biggest of the home / draw / away probabilities) — so you can see whether it is as reliable on toss-ups as on heavy favourites.

Favourite confidenceMatchesBrier
P_fav < 40%810.649
P_fav 40-60%4760.633
P_fav 60-80%3180.512
P_fav >= 80%1120.428
  • Out-of-sample: the calibration layer is refit per tournament on pre-tournament data, so these numbers do not reuse the live shipped calibrator (which has seen these results).
  • The uniform 1/3 forecast scores a Brier of 0.667; lower is better. Major-tournament football is high-variance, so a strong model still sits well above a league-season Brier.
  • Calibrated and uncalibrated metrics are reported on the same fixtures so the calibration layer's effect is visible.

Built 2026-05-30 · model 1.0.0 · calibration layer refit on the 24 months before each tournament.

Copa do Mundo 2026 — acompanhamento ao vivo

Live grading begins once matches are played. Until then, the scoreboard above already grades the model on past tournaments, and the full method is on the methodology page.

No scored matches yet

First scored match expected 2026-06-11. Once the first match is played, this page grades the model in real time: a running accuracy chart and day-by-day breakdown, updated after every game.

Nothing to show yet: the forecasts already exist on each match page, but no games have been played to test them against. For the record so far, the scoreboard above grades the model on past tournaments.

Reliability diagram

Not enough matches yet to draw this. None graded yet; it appears once at least 50 are in. Until then, the scoreboard above already shows this same chart for past tournaments, and the full backtest is on the methodology page.

Brier by competition

SegmentMatchesBrierΔ vs overall
World Cup 2026

Brier by tournament stage

SegmentMatchesBrierΔ vs overall
Group stage
Round of 32
Round of 16
Quarter-final
Semi-final
Third-place play-off
Final

Brier by favourite confidence

SegmentMatchesBrierΔ vs overall
P_fav < 40%
P_fav 40-60%
P_fav 60-80%
P_fav >= 80%

O que os três números significam

Pense em um meteorologista. Qualquer um pode dizer "70% de chance de chuva." Os bons acertam cerca de 70% das vezes quando dizem isso. Esses três números verificam o modelo da mesma forma.

  • Brier score — as probabilidades ficaram perto da realidade? Para cada jogo, medimos quão longe a previsão ficou do que realmente aconteceu e tiramos a média. Uma bola de cristal perfeita pontua 0; chutar 1 em 3 toda vez pontua cerca de 0,667. Quanto mais baixo, melhor.
  • Log loss — a mesma ideia, mas excesso de confiança é punido com força. Declare algo quase certo e erre, e esse número dispara. É a métrica que mantém o modelo humilde. Chutar cego pontua cerca de 1,099. Quanto mais baixo, melhor.
  • ECE — "70%" realmente significa 70%? Reunimos todas as previsões de "cerca de 70%" e verificamos com que frequência essas coisas realmente aconteceram. A diferença média, em todos os níveis de confiança, é o ECE. Poucos pontos percentuais significam que as probabilidades declaradas podem ser lidas pelo valor de face. Quanto mais baixo, melhor.

Os dois primeiros recompensam ser preciso e ousado; o último é a verificação de honestidade. Um modelo pode parecer impressionante e ainda assim exagerar sua confiança — medir os três juntos é o que detecta isso.

Quer a mecânica por trás — os modelos componentes e o teste fora de amostra por trás desses números? Está tudo na página de metodologia.

As métricas nesta página são a calibração do próprio modelo, avaliada contra os resultados observados — as probabilidades previstas comparadas com o que realmente aconteceu em campo.

Calibração durante o torneio · onthepitch · onthepitch