# tennis_matrix

tennis_matrix, an Octave code which computes the transition matrix for a game of tennis, which has 17 distinct states.

The peculiar tennis scoring system goes 0, 15, 30, 40, Win. However, to win, a player must be ahead by two points.

There are three "peculiar" states: Deuce, Ahead 1, Behind 1, which arise when one player is near to winning. 'Ahead 1' means the player is 1 point away from winning. 'Behind 1' means the player is 1 point away from losing. 'Deuce' means either player will win with two unopposed points.

This code assumes that the server has a constant probability p of scoring each point. The transition matrix can be used to model a particular game, given the value of p. Eigenvalue analysis or numerical simulation can then predict the likelihood that the server will win. Estimates can be made for the number of serves required in a complete game.

### Languages:

tennis_matrix is available in a MATLAB version and an Octave version.

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### Reference:

1. James Sandefur,
A Geometric Series from Tennis,
College Mathematics Journal,
Volume 36, Number 3, May 2005, pages 224-226.
2. Ian Stewart,
Game, Set, and Math,
Penguin, 1989.