Choose your event
Start with the Classic 37 wheel or build your own. Pick a sector, color, category, or custom group to investigate.
Your pocket probability lab
Make chance
make sense.
Spin, predict, and experiment your way to understanding probability. Crimson Sector turns abstract math into something you can see, test, and truly grasp.
- Free
- No account
- Works offline
Event to study
Crimson 3 of 8 sectors
Theoretical chance3/8
As a percentage37.50%
The result is drawn before the wheel moves.
05guided lessons
500spins in one series
00data collected
From question to discovery
Don't just memorize it.
Experiment with it.
Probability becomes clearer when you can change the rules, test a prediction, and see exactly what happens.
Spin and predict
Read the theoretical probability, lock a forecast, then run one spin or a whole series of 10, 50, 100, or 500.
See theory meet practice
Follow every result in Analysis. Watch short series wander and long series settle around the theory.
One lab. Every angle.
Built for curious minds
From your very first fraction to the law of large numbers — learn at your own pace, with no stakes and no pressure.
Learn probability in plain words
Five short Academy lessons pair live examples with tasks that explain every answer — including every mistake.
Build your own wheel
Create custom sectors, categories, colors, and weights. Equal or weighted — you decide how chance works.
Watch the pattern emerge
Charts compare expected and observed results, so randomness becomes something you can reason about.
Put your intuition to the test
Lock a prediction before the experiment begins. Compare your forecast with the result and sharpen your thinking.
Your experiments stay yours
No account, analytics, ads, or tracking. Everything is stored only on your device, and the app works fully offline.
A little momentum goes a long way
Take on a daily challenge and earn learning badges for lessons, predictions, experiments, and custom wheels.
First SpinLong RunGraduateMyth BusterWheelwrightForecaster
The big idea
Short series wander.
Long series settle.
The wheel has no memory. Discover the law of large numbers through real experiments, not just a definition.
Probability of an eventfavorable ÷ totalCount carefully. Every sector belongs in the total.
Talk to a human
Questions?
We're listening.
Need help, found something unexpected, or have an idea for the lab? Send a note — feedback is always welcome.
post@hentycoon.click
Enter the lab
Ready to look chance
in the eye?
No money. No stakes. No prizes. Just the mathematics of random events, made wonderfully clear.
Download on the App Store