The shape of chance.
Click the board to drop a ball, or hold and drag to pour.
Live readout
Balls dropped0
Mean slot—
Spread σ—
Center share—
Bell-curve fit—
Drop a few balls — they'll pile up into a normal distribution under the pegs.
The yellow line is the ideal normal curve, fitted live to your data.
Each ball follows its own path — a chain of tiny random bounces, left or right off every peg it meets. Drop enough of them and the chaos resolves, every time, into the same gentle curve. This is a Galton board; the shape it builds is the normal distribution.
Source: Galton's bean machine