The model & methodology

Every probability you see on this site comes from a Monte-Carlo swarm — 4,200 independent simulations of the full World Cup bracket. Each agent perturbs the 48 teams' Elo ratings with Gaussian noise (σ = 58), then plays every match of the 104-match tournament, sampling goal counts from a Poisson distribution informed by each team's attack and defence rate. Aggregate the 4,200 outcomes → you get the title %, final %, semi %, and advance % for every team.

The whole engine lives client-side in src/lib/swarm-engine.ts. Hitting Re-run swarm on the /odds-model page reseeds the random number generator and runs all 4,200 agents again — typically about 4 seconds on modern hardware, with progress streamed in 350-agent chunks so the UI stays responsive.

⚠️ Elo ratings are informed June-2026 estimates, not official FIFA figures. The Poisson scoring is a deliberate simplification — real football has correlated goals, fatigue, red cards, set-piece variance and all sorts of dynamics this model ignores.

Pick HOME, DRAW or AWAY for every match. Locked picks are saved to your account (auth-gated).

• api-football →Live fixtures, results, lineups (when activated)
• StatsBomb →Historical xG and event data for the all-time records (research-only)
• Wikipedia REST →Player biographies + photos in the player panel + edition history
• FlagCDN →All flag images served via https://flagcdn.com
• Anthropic Claude →Conversational agent at /agent (claude-haiku-4-5 streaming)

Elo rating

A numeric strength index for each team. Higher = stronger. Updates after every match based on the result, opponent strength, and venue. 2026 Elos are informed June-2026 estimates, not official FIFA figures.

Title %

Estimated probability that a team wins the entire tournament, derived from running the full bracket thousands of times with perturbed Elos.

Advance %

Probability of progressing past the group stage.

Final / Semi %

Probability of reaching the Final / Semi-finals respectively.

GD

Goal Difference — goals scored minus goals conceded across all group games. Used to break ties.

xG

Expected Goals — a measure of shot quality. Sum of probabilities that each shot would result in a goal.

Poisson model

A statistical distribution used to simulate match scorelines based on each team's attack/defence rates.

Swarm

The collective output of 4,200 parallel simulations, each with slightly different inputs. Robust against single-run variance.