There are two reasons why this variant of Tic Tac Toe is useful for separating effects of importance and predictability on acoustic prominence. First, defining importance within the context of play tic tac toe is straightforward. An utterance that introduces a game move that wins or blocks the win of a game can be defined as more important than an utterance introducing a move that does not win or block the win of a game.

This is particularly advantageous because defining importance is difficult in most conversations. Importance can vary depending on the task, conversation, and intentions of the interlocutor--a point that Bolinger (1972) aptly summarized with the title of his classic article: “Accent is predictable (if you are a mind reader)”. Within the context of Tic Tac Toe, however, importance is easily operationalized