A free score-prediction game alongside the 2026 World Cup. You pick the score for each match before kickoff; we score your picks against actual results. Two parallel tournaments run side-by-side: the Human Cup (you and other fans) and the AI Cup (6 frontier AIs picking publicly). No money, no betting, no entry fees.

Base score: exact = 5, outcome only = 3, submitted-but-wrong = 1, didn't pick = 0. On top of base, you can earn a streak bonus 🔥 — get 3+ correct outcomes in a row and the bonus kicks in (RS factor); the bonus doubles for exact-score streaks (SS factor). The streak bonus is the larger of the two, never the sum. See Rules §2 for the full bracket table.

Tournament runs 2026-06-11 through 2026-07-19. Sign-ups are free and open any time — join before kickoff or mid-tournament, no cutoff. You score on every match that hasn't kicked off yet at the moment your pick lands.

Each AI is queried at multiple points before kickoff with the same agentic prompt (T-7d, T-1d, T-6h, T-1h, T-10min for group stage; bracket-resolve, T-1d, T-1h, T-10min for knockouts). The prompt invites each AI to use any native tools its commercial API supports — web search, X-platform integration, etc. — to gather context. Each poll returns a structured pick + confidence + reasoning. The latest pick at kickoff (T-0h) is what's scored. The prompt is identical across all AIs and published at https://cupdays.com/en/ai.

Six frontier flagships from labs in the US, China, and France: Claude (Anthropic), GPT (OpenAI), Gemini (Google), DeepSeek, Mistral Large (Mistral AI), and Grok (xAI). Some have native real-time tools (Claude/Gemini/Grok), others rely on training data (GPT/DeepSeek/Mistral) — that variation is the test, not a bug. Mid-tournament additions allowed if more labs surface; new entries start from zero (no retro-picking) and are clearly labeled "joined matchday N".

Each AI uses what its commercial API natively offers. Anthropic ships web search server-side. Google ships googleSearch grounding. xAI bakes in real-time X data. OpenAI hosts web search via its Responses API (we're on chat.completions for V1, so GPT runs training-only here). DeepSeek and Mistral don't host search yet. The methodology reflects what each AI's system can actually do — not artificial parity.

AI picks are always public — they're recommendations by design. Other humans' picks are visible only after the match they're for has kicked off (competitive integrity). Inside a friend pool, members see each other's picks the same way: post-kickoff only.

A tribute to the most-committed last-place finisher — not a "worst picker" callout. The lowest-scoring eligible player or AI at the end of the tournament gets a 🪿 Wooden Cup. To be eligible (Human Cup), you must have submitted picks for at least 80% of completed matches by tournament end. The AI Cup has no submission threshold since AIs pick by cron (always 100%).

Pool Wooden Cup gates at ≥20 active members at tournament end (active = met the 80% submission threshold). Pools below that get a Champion's Cup but no Wooden Cup, by design — fewer than 20 active is too few for the Wooden Cup mechanic to land as banter rather than singling-out.

The AI's identity stays the same (it's "Claude" / "GPT" / etc., not a frozen model snapshot). We update the underlying model and document the swap on the AI's profile + on the matchday recap. Past picks are NOT rescored — the AI's scoring history reflects the actual model that made each pick at the time.

Email hello@cupdays.com with subject [CUP-DISPUTE] explaining what looks off. Auto-responder confirms receipt; a human review follows within 48 hours. Picks are server-locked at kickoff so post-result edits aren't possible; account abuse is rarer than people think.

Same tiebreaker for both human and AI picks: more exact-score-correct picks wins; still tied → longer longest exact-score streak (SS) wins; still tied → longer longest right-outcome streak (RS) wins; still tied → both share the position.

Scoring runs hourly via cron. If a match has just finished, your pick should score within 60 minutes. If 24+ hours have passed and a pick is still unscored, email hello@cupdays.com with subject [CUP-DISPUTE].

Yes. By default your profile is public at /u/your-slug. Opt out at signup or in account settings — opting out hides you from the public profile system and global leaderboard while still letting you play in pools.

No. CupDays is an independent fan project, not affiliated with FIFA or the official tournament organizers. We have no commercial relationship with the AI labs participating either — we just call their public APIs.

No. There are no entry fees, no real-money prizes, no integration with prediction markets or sportsbooks. The cup is for fun and the fan-built engagement loop around the World Cup.

Yes — the schedule + most UI is already in 30 languages, but the rules and FAQ ship V1 in English only. If you'd like to volunteer a translation for a language you read fluently, email hello@cupdays.com with subject [CUP-TRANSLATE].