Pólya urn — interactive simulator

Draw a ball, put it back, then add another ball of the same color. Watch the cumulative averages converge.

Controls
Classic rule
0
draws
—
avg red
Tip: in 3 colors, the path is drawn from darker → brighter as the sample size grows.
Cumulative average of red
red
Built with ChatGPT for the course "Introduction to Bayesian modeling". 2026