The Plinko / Galton Board: A Visual Guide to Randomness and Probability

What is the Plinko / Galton Board?

The Plinko / Galton Board is a device consisting of a vertical board with rows of evenly spaced pegs. Balls are dropped from the top and bounce down, taking a path determined by chance as they hit each peg. The final positions of the balls form a distribution that resembles the normal distribution.

This concept was first described in 1894 by Sir Francis Galton to demonstrate how small variations can lead to predictable patterns over time.

How Does It Work?

Each ball's path is determined by the random collisions with each peg. The probability of a ball going left or right at each peg is equal, leading to a binomial distribution as more balls are dropped.

As the number of balls increases, the resulting distribution approximates the normal distribution, illustrating the Central Limit Theorem.

Why Does It Matter?

The Plinko / Galton Board is a simple model that demonstrates complex statistical concepts. It helps in understanding probability distributions and their applications in fields such as finance, physics, and data science.

It also provides an intuitive way to visualize the Central Limit Theorem, which states that the sum of many independent random variables will tend to be normally distributed.

Real-World Applications

The principles behind the Plinko / Galton Board are used in various real-world applications. For example, they can model the spread of diseases, predict stock market fluctuations, and analyze traffic patterns.

In physics, similar models are used to simulate particle movements and understand diffusion processes.

Frequently asked questions

Try it live

Everything above runs in your browser — open Plinko / Galton Board — Three.js Simulation and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.