Keep or toss
Most weak charts are not badly drawn. They are the wrong chart for the question. A pie chart asked to show a trend, a line drawn between cities that have no order, a radar chart asked to rank 25 countries: each looks finished and answers nothing.
This game trains the check that prevents that. Every card pairs a question someone might ask in a meeting with a chart type. Keep the card when the chart answers the question well, toss it when it does not. After each call a short line explains why, so the reasoning builds up over a dozen rounds.
The logic behind the answers is the same one chart choosers use: first name the relationship in the data. Is it a comparison between categories, a change over time, parts of a whole, a distribution, a relationship between two measures, or a ranking? Then count what you have: how many categories, how many points in time, how many series. Those two steps rule out most charts before any design work starts. Some questions appear twice with different charts, because the same question can be answered well or badly.
Twelve cards
Each card pairs a question with a chart type. Keep the card if the chart answers the question well, toss it if it does not. Twelve cards per game, drawn from 22. Drag the card right to keep or left to toss, use the buttons, or press the right and left arrow keys.
Card 1 of 12Score 0
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Line chart
How did monthly sales change over 12 months?
Keep. Twelve points in time order are what a line chart is for; the slope shows the trend.
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Pie chart
How did monthly sales change over 12 months?
Toss. A pie shows shares of one whole. Months are a sequence, and twelve slices hide the trend.
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Sorted bar chart
Which of 5 regions sold the most last year?
Keep. Sorted bars from a zero baseline make the leader and the gaps obvious.
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Pie chart
What share of the budget goes to each of 3 departments?
Keep. Three parts of one whole is the case where a pie reads well.
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Donut chart
What share of revenue comes from each of 14 products?
Toss. Fourteen slices are too thin to compare. Sorted bars with percentages work better.
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Histogram
How are delivery times spread across 800 orders?
Keep. Binning 800 values shows the shape of the spread, including a long tail.
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Pie chart
How are delivery times spread across 800 orders?
Toss. A pie cannot show a distribution; it only splits a total into shares.
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Scatter plot
Does ad spend relate to sign-ups across 60 cities?
Keep. One dot per city placed by both values shows whether they move together.
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Dual-axis line chart
Does ad spend relate to sign-ups across 60 cities?
Toss. Cities have no order, so lines between them mean nothing, and two scales can suggest any link you like.
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Bump chart
How did the ranking of 8 teams change across 10 seasons?
Keep. A bump chart plots rank per season, so every overtaking move is a crossing line.
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Waterfall chart
How did profit get from last year's figure to this year's, step by step?
Keep. Floating bars show each gain and loss between the start and end totals.
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3D pie chart
How did profit get from last year's figure to this year's, step by step?
Toss. A pie has no sequence and no negatives, and the 3D tilt distorts every slice.
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Slope chart
How did satisfaction at 4 stores change between 2024 and 2025?
Keep. Two dates and a few items: the angle of each line shows the change.
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Radar chart
Which of 25 countries has the highest literacy rate?
Toss. Radar axes are hard to compare and 25 spokes are unreadable. Sort the countries in a bar or dot plot.
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Dot plot
Which of 25 countries has the highest literacy rate?
Keep. Sorted dots fit 25 rows on one slide and make the ranking easy to scan.
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Box plot
How do salaries compare across 6 departments, including the spread?
Keep. Boxes line up the median and the middle half of each department side by side.
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Stacked area chart
How did the market share of 3 browsers shift over 15 years?
Keep. A few parts of a whole over many years is the use case for stacked areas.
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Line chart with 12 lines
How did 12 product lines each trend over 5 years?
Toss. Twelve crossing lines become spaghetti. Small multiples give each line its own panel.
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Heatmap
Which hours and weekdays are busiest at a help desk?
Keep. A grid of weekday by hour, shaded by volume, shows the busy blocks at once.
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Column chart
How did the daily temperature change across a whole year?
Toss. 365 columns turn into a dense comb. A line shows a long daily series more cleanly.
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Treemap
Which 3 of 40 suppliers deliver late most often?
Toss. A treemap shows parts of a whole, not a ranking; rectangle areas are hard to order. Use sorted bars.
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Grouped bar chart
How do this year and last year compare in 4 regions?
Keep. Two bars per region put each year-on-year comparison side by side.
Questions
What does Keep or Toss train?
Matching a question to a chart type. Change over time usually wants a line, a comparison between categories wants sorted bars, a share of a whole wants a stacked bar or a pie with few parts, a spread of values wants a histogram and a link between two measures wants a scatter plot. Each card tests one of those pairings.
Why does the pie chart get tossed so often?
A pie only answers one kind of question, how a whole splits into a few parts, and it answers it through angles, which people read less precisely than lengths. As soon as a question compares categories, tracks time or involves more than about five parts, a bar or line chart does the same job more clearly.
When is a slope chart the right answer?
When there are exactly two points in time and several items to compare, such as satisfaction at four stores in two years. Each item becomes one line between the two dates, and the angle of the line shows at a glance which items rose, which fell and by how much.
Where is the best score stored?
Only in this browser, in local storage on this device. Nothing is sent to a server, there is no account, and clearing the site data in the browser resets the score to zero.