Randomized Tic-Tac-Toe: An Educational and Fun Class Project

Music City Center 

As (almost) everybody knows, the game of tic-tac-toe can end in any one of three outcomes: 1) Player X (who moves first) wins; 2) Player O (who moves second) wins; 3) The game is a draw. Furthermore, almost everybody knows that if both players know what they are doing, the game is guaranteed to end in a draw (often called a "cat's game").

Suppose now that both players make each of their moves at random. For such a game (called "randomized tic-tac-toe") all three of the outcomes listed above can occur. In this presentation the probabilities associated with each of the three outcomes will be determined.

These probabilities were originally determined by the presenter (with the assistance of a statistics major working on his senior project) in the spring quarter of 2004. Recently the presenter incorporated this problem into his statistics courses as a "class project". Thus, this presentation will also include a discussion of the class projects.

randomized tic-tac-toe

class projects 

Section on Statistics and Data Science Education