Maven (Scrabble)

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Maven is the current best known artificial intelligence Scrabble player, created by Brian Sheppard. It has been used in official licensed Hasbro Scrabble games, and the downloadable Funkitron Scrabble.

[edit] Algorithms

Maven's game play is sub-divided into three phases: The "mid-game" phase, the "pre-endgame" phase and the "endgame" phase.

The "mid-game" phase lasts from the beginning of the game up until there are nine or fewer tiles left in the bag. The program uses a rapid algorithm to find all possible plays from the given rack, and then part of the program called the "kibitzer" uses simple heuristics to sort them into rough order of quality. The most promising moves are then evaluated by "simming", in which the program simulates the random drawing of tiles, plays forward a set number of plays, and compares the points spread of the moves' outcomes. By simulating thousands of random drawings, the program can give a very accurate quantitative evaluation of the different plays.

The "pre-endgame" phase works in almost the same way as the "mid-game" phase, except that it is designed to attempt to yield a good end-game situation.

The "endgame" phase takes over as soon as there are no tiles left in the bag. In two-player games, this means that the players can now deduce from the initial letter distribution the exact tiles on each other's racks. Maven uses the B-star search algorithm to analyse the game tree during the endgame phase.