The 45% Problem

Probabilistic pricing for FIFA World Cup 2026. M★ is a bivariate Poisson model with Dixon-Coles correction, calibrated on international match data and compared nightly to bookmaker-implied probabilities. The “45% problem” refers to a systematic divergence documented in Phase 1: market-implied championship probabilities for mid-tier contenders cluster near 45% of their model-implied values, suggesting a persistent structural mispricing that motivated this research programme.

Pre-registered at osf.io/spmkg · tag v1.0.0-mstar-lock · Phase: group stage · 94 matches remaining

A mathematical representation of 10,000 Monte Carlo samples from the M★ posterior, projected onto the FIFA World Cup trophy.

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§ 0 · Scenario

Call the final four.

Enter the simulator →

Pick four semifinalists. The model has run 10,000 simulated tournaments. See where your scenario lands.

§ 1 · Championship pricing

Tournament leaderboard

MODEL STATE · 2026-06-15

All 48 teams →

#	Team	Conf.	Champion	Final	Semi	95% CI
01	ESP Spain	UEFA	18.7%	30.9%	42.4%	[0.180, 0.195]
02	FRA France	UEFA	14.4%	22.0%	27.3%	[0.138, 0.151]
03	ARG Argentina	CONMEBOL	14.2%	22.1%	27.4%	[0.136, 0.149]
04	ENG England	UEFA	8.9%	15.2%	19.9%	[0.083, 0.095]
05	BRA Brazil	CONMEBOL	6.3%	13.9%	30.0%	[0.059, 0.068]
06	MAR Morocco	CAF	5.8%	12.7%	28.6%	[0.053, 0.063]
07	NED Netherlands	UEFA	4.8%	10.1%	17.7%	[0.044, 0.053]
08	POR Portugal	UEFA	3.6%	7.2%	10.1%	[0.032, 0.040]

§ 1.5 · Modal path

Most likely bracket

Full bracket →

Each match shows the posterior probability that the favoured side advances. Click a team to open its progression page. The chain · R16 through final: is the sequence of modal outcomes; its joint likelihood is much lower than any leg alone.

Stage 1 · 14 · 18 Jun

Round of 16

R16 · Match 01

R16 · Match 02

R16 · Match 03

R16 · Match 04