Probability describes situations where a random sample is selected from a population. It is also used to model a variety of other situations involving randomness.

Tennis match

A simple model for a tennis match between two players, A and B, assumes that:

A more complex model might introduce more parameters to relax the assumption of independence.

Simulation

For any values of π1 and π2, we could randomly generate the results of successive points until a match was complete.

This generates an instance of the model and is called a simulation.