Extraplot is a drawing game about real data, not a quiz. You are never asked to name a country, pick a year or remember a number. You are shown a real chart that stops at a marked year and asked one thing: where did the line go next?
The chart is drawn from public records — the World Bank, Our World in Data, US Social Security name data, Wikimedia pageviews and published industry figures. Every value before the cut-off is real. Every value after it is hidden until you commit to a line and press Ink it in. If you want the one-paragraph version first, read What is Extraplot? for the short version and come back.
A round in five charts
A daily set is five charts. Two are warm-ups, where the recent trend is on your side. Two are medium — history helps, but history bends. The last is a bold call, where the honest answer is that nobody saw it coming. The order is deliberate: you start with a chart you can reason your way through, and end with one where you have to think harder about mechanisms than about the last two data points.
There is no timer. The clock only matters for one thing: the day resets at midnight Eastern Time, and everyone in the world plays the same five charts before that reset. Nobody gets an easier set because of where they live or when they wake up.
Step by step
- Read the chart. The title is a question, the unit is on the axis, and the note under the title gives context. The real line runs left to the dashed cut-off. Everything to the right of the cut-off is yours.
- Start from the last real point. Your line is anchored there automatically. The first thing to decide is the direction the next year took — which is usually easier than deciding the last one.
- Draw across the shaded side. Drag left to right and the game records a value for each hidden year. You do not need to hit every year precisely; the line is interpolated between the points you set.
- Adjust without penalty. Draw over a stretch to replace it. Undo removes a whole stroke. Start over clears the drawing. Nothing is final until you ink it in.
- Ink it in. The truth appears over your line, the score counts up, and a short note explains what actually happened in the hidden window. The source link is there if you want to check the numbers yourself.
- Repeat for five charts. The progress pips show where you are. Your day ends with a total, a band label and a spoiler-free result you can share.
Mouse, touch and keyboard
The chart is a real drawing surface, not a form. Any input method that can set a value for a year works.
| Action | Mouse | Touch | Keyboard |
|---|---|---|---|
| Move along the years | Drag horizontally | Drag horizontally | Left / Right arrow |
| Set the value for a year | Drag vertically while dragging | Drag vertically | Up / Down arrow |
| Jump to first or last hidden year | Drag to the ends | Drag to the ends | Home / End |
| Submit the drawing | Ink it in button | Ink it in button | Tab to the button and press Enter |
| Undo a stroke | Undo button | Undo button | Tab to Undo and press Enter |
The exact scoring curve
Each chart is scored on mean miss ratio: the average gap between your drawn line and the true line across the hidden years, divided by the chart's height (the fixed y-axis span). The curve is the same one the game uses at reveal, so you can reproduce a score by hand.
Let r be the mean miss ratio. If r is at most 0.01 — a miss of 1% of the chart height on average — you score the full 1,000. Between 0.01 and 0.31 the score falls linearly. At 0.31 or more, the chart scores 0. In one line: score = round(1000 × clamp(1 − (r − 0.01) / 0.30, 0, 1)).
| Average miss (share of chart height) | Score for the chart |
|---|---|
| 1% | 1,000 |
| 5% | 867 |
| 10% | 700 |
| 16% | 500 |
| 20% | 367 |
| 25% | 200 |
| 31% or more | 0 |
A perfect day is 5,000. A good day is somewhere around 3,000–3,800: close on the warm-ups, a little off on the bold call. The formula is deliberately forgiving of one bad year and unforgiving of a wrong direction across the whole window, because direction is the thing worth knowing.
House lines and lazy lines
Two fake lines are drawn on every chart before it is allowed into the game: a flat line holding the last visible value, and a trend line carrying the trend of the last ten visible years straight on. Both are scored with the same curve as you.
If either would have scored above 450, the chart is rejected and replaced. This is the game's no-lazy-lines rule: a chart where holding the last value nearly works is not a question worth asking. Every Extraplot chart has something to say about the world.
At reveal you also see what those two lines would have scored. Beating both of them on all five charts earns a House Beater badge. It is a small, strangely satisfying thing.
Difficulty labels
Charts are labelled by how easy they are to bluff, not by how famous the topic is. A chart about a very famous product can be hard if its growth was strange; a chart about an obscure country can be a warm-up if the trend is steady.
- WARM-UP — the recent trend is on your side. Extend what you see, but not carelessly.
- SQUINT — history helps, but history bends. Expect a turning point somewhere in the hidden window.
- BOLD CALL — nobody saw this one coming. The chart's hidden years contain a shock, a saturation or a reversal.
Six habits that score
- Trust mechanisms more than the last slope. Adoption saturates, prices mean-revert, populations compound, fashions collapse. Ask what kind of curve you are looking at before you draw the first year.
- Watch the ceiling and the floor. A percentage cannot pass 100. A share cannot drop below zero. A count of devices can fall faster than it rose. Charts are filtered for padded axes, but the real world still has hard limits.
- Think about the world, not the chart. The cut-off year is a clue: a 2019 cut-off for a travel metric means something different from a 2014 cut-off for a streaming service. What happened next, and how big was it?
- Get the direction and the ending right. The average miss rewards the whole shape. Nailing the endpoint and the general path beats obsessing over year-to-year wiggles.
- Use the keyboard for precision. Drag for the rough shape, then arrow-key the last few years. A one-year spike that never appeared in the truth costs you more than it seems.
- Practise without pressure. Archive runs and practice mode do not touch your daily streak. If a category keeps beating you, favourite it and learn its habits.
Accessibility and comfort
Extraplot is free and needs no account. Progress lives in your browser's local storage only — there is no email, no sign-up and no server-side profile. Every control is reachable by keyboard, focus is visible, colour is never the only signal on the reveal, and the interface respects your operating system's reduced-motion setting (with an in-game toggle if you want it differently).
The drawing surface has a described-by paragraph for screen readers and a live readout of the selected year and value. Sound effects can be switched off. There is no timer, no streak penalty for missing a day's first chart, and no penalty for undoing your work.