How to Play

Choose an answer or estimate a number

In a choose-an-answer round, you receive a target number and a named answer pool. Search that pool and select the answer that comes closest. You are choosing from this question’s pool, not every possible answer in the world.

In an estimate-a-number round, type your estimate in the displayed unit. Years must be whole numbers. Units do not switch automatically.

An accepted answer locks the round. An unrecognised name or invalid number does not lock it, but the timer keeps running in timed modes.

Daily or Unlimited

Daily contains seven fixed questions for each topic. A new set begins at 00:00 UTC, and each round gives you 30 seconds. Your first completed attempt is your Daily result for that topic and date. Later attempts are labelled Practice.

Unlimited creates another seven-question run. Relaxed mode has no timer; timed mode gives you 30 seconds per question. Choose before starting: you cannot change the timer halfway through a run. The starter bank is limited, so questions will repeat.

Understanding your score

Each round awards up to 1,000 points, for a total of 7,000. There are no speed bonuses, lives, or double-score rounds.

For the expanded scale-v1 bank, each metric has its own scoring scale. A difference equal to that scale is worth about 500 points, after accounting for the closest available answer. Earlier pixel-v1 Daily sets use their original proportional or absolute-distance rules. Results keep the rule version used when they were played.

For choose-an-answer questions, the nearest available answer earns full points even when nothing matches the target exactly. Equally near answers receive the same credit. For numerical estimates, source precision is used when checking an exact answer. A score rounded to 1,000 does not necessarily mean the value was exact.

Between rounds and local saves

After submitting, review the answer, difference, score and source. The next timer starts when you select Next Round. Opening another tab or refreshing during a timed question does not restart its timer.

Progress and records are saved in this browser when local storage is available. They do not automatically sync to another device. Private browsing, clearing site data, or storage restrictions can remove them. Visit Your Records to export a backup. Scores are local and are not verified global rankings.