How to play
Ninety
Five unknowns. Give ranges wide enough to be right nine times in ten.
- Five quantities, one at a time. You will not know most of them.
- For each, give a low and a high figure you are 90% sure the answer falls between.
- Lock it in and the answer appears straight away, on the same scale you typed against and drawn where a picture helps: a globe for a distance, a ladder of things you already know for a height or an area.
- Knowing the last answer is allowed to change the next range. That is the game teaching you to widen.
- Prefer the suspense? A button on the answer screen holds all five back until the end instead.
How it is scored
Calibrated means about nine of your last ten ranges contain the answer. Hits count, and narrowness counts: a range from zero to a trillion always hits and scores nothing. Miss more than one and you are overconfident, which is the usual result. Hit all five easily and your ranges were too wide.
Most people hit two or three out of five on their first go. That gap is the point of the game.
How to get better at it
Your ranges should feel uncomfortably wide. Aiming to hit nine out of ten means planning to miss one, and almost everybody's first instinct is far too narrow.
Anchor on something you actually know and multiply from there. You may not know a mountain's height, but you know roughly how tall a tall mountain is, and that is enough to bound it.
Think in multiples, not increments. Width is measured as a ratio, so 100 to 1,000 costs the same as 1,000 to 10,000. Widening a range you are unsure about is cheap; being wrong is not.
If you hit five out of five, you were too cautious rather than brilliant. That is why the game says so.
When it resets
New puzzle at midnight UTC, so everyone is answering the same question at the same moment.