Arena

The question

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. 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 print Tickerz reads of 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 print. It is the Arena's number, not an official one.

The seal

At the first run after close, every forecast that stands is hashed and stamped with OpenTimestamps. The exact text hashed is served with the question.

What it is not

Points only. No money, no prizes. Not advice.

For code: GET /api/arena, GET /api/arena/question/{id}, POST /api/arena/forecast, and the MCP tools arena and submit_forecast.