World charts are the backbone of Extraplot. Each one is a real annual series for a single country — published by the World Bank, Our World in Data or a comparable public source — cut off at a year, with five to twelve hidden years for you to draw.
The questions are deliberately ordinary and specific: how quickly did internet use spread in Brazil? What happened to South Korea's fertility rate after 2015? Did life expectancy in a country recover after a shock? The chart is not about knowing the exact number. It is about knowing the direction, the pace and the shape of a demographic or economic transition.
What kinds of charts appear
- Demography: birth rates, fertility, life expectancy, child mortality, population ageing.
- Development: income per person, electricity access, internet use, university enrolment, urbanisation.
- Environment: forest cover, emissions per person, water use, renewable energy share.
- Health: maternal health, tuberculosis incidence, health spending as a share of GDP.
Two charts can look similar and behave completely differently. A share — internet users as a percentage of the population — has a hard ceiling at 100 and usually follows an S-curve: slow start, fast middle, slowing end. A rate such as births per woman has no such ceiling and can fall straight through the floor: a fertility collapse looks like a slide, not an S.
How scoring behaves on world charts
Long country series are where careful players beat bold players. The visible trend is usually informative, but the same chart is only allowed into the game if carrying that trend forward would score 450 or less — so on medium and hard charts, something bent in the hidden window.
The most common bend is a transition finishing: an S-curve running out of people to connect, a fertility rate stabilising after decades of decline, a mortality rate approaching a floor. The second most common is a shock: a recession, a conflict, a pandemic, a policy change. Look at the cut-off year as a historical clue.
Drawing advice for country data
- Check whether the metric is a rate, a share, a count or an index. Each has a different relationship with its limits.
- Ask how far the transition has already gone. A country at 15% internet access has room for a fast rise; a country at 85% does not.
- Expect convergence, not divergence: most development indicators move toward a ceiling and flatten.
- Treat a cut-off in 2019, 2020 or 2021 as a strong hint that the hidden window contains a disruption.
- Do not draw year-to-year noise. Country data is smoothing by nature; the reveal rewards the shape.
Why the category is bigger than the rest
Country data makes up roughly a third of the season. That is partly supply — there are thousands of usable indicator-country pairs — and partly design: the questions are universally legible. You do not need to follow a specific industry or pop culture to have an opinion about whether a country's life expectancy rose or fell after a difficult decade.
It is also the category that most rewards replaying. An archive day with a country chart you got badly wrong is worth more than five new charts you got right; the reveal note usually names the exact year of the turn, which is the piece you were missing.