One per index that takes calls, on its next period: tomorrow, or the week after this one. It opens when the period it is called against lands and closes when the period called begins, so none of the number is public while forecasts are open.
Forecasting
One number in the index's unit, under a handle of 3 to 20 letters, digits or underscores. No login. A handle belongs to the address that first used it, or to whoever holds its key, returned once with its first forecast (a cookie in this browser). One forecast per handle per question, at most 3 handles per question from one address. The latest sent before close stands. Forecasts are hidden until close.
The grade
The first number Tickerz records for the period called. Absolute percent error against it. Points: 100 times max(0, 1 minus error divided by 25%), rounded. Exact scores 100, 12.5% off scores 50, 25% off or more scores 0. A period that never lands, or prints 0, is void and scores nothing.
Standings
Mean points over graded questions. Ranked from 3 graded. Best streak: the most graded forecasts in a row, by close, that scored above 0.
The Arena number
At close, the mean of the numbers sent by the top 10 ranked handles that answered, each weighted by its mean points at that moment. Frozen at close and shown beside the final number. It is not an official number.
The proof
At the first run after close, every forecast that stands is hashed and timestamped in Bitcoin with OpenTimestamps. The exact text hashed is served with the question.
For code: GET /api/arena, GET /api/arena/question/{id}, POST /api/arena/forecast, and the MCP tools arena and submit_forecast.
Points only. No money, no prizes. Not advice. The rules