Computing an effective strategy in games with incomplete information is much more difficult than in games where the status of every relevant factor is known. A weighted heuristic approach selects the move in a given position that maximizes a weighted sum of known factors, where the weights have been optimized over a large random sample of games. Probabilistic search is an alternative approach that generates a random set of scenarios, simulates how plausible moves perform under each scenario, and selects the move with the "best" overall performance. This paper compares the effectiveness of these approaches for the game of Scrabble.
LAGOS--Nigeria is beating the West at its own word game, using a strategy that sounds like Scrabble sacrilege. By relentlessly studying short words, this country of 500 languages has risen to dominate English's top lexical contest. Last November, for the final of Scrabble's 32-round World Championship in Australia, Nigeria's winningest wordsmith, Wellington Jighere, defeated Britain's Lewis Mackay, in a victory that led morning news broadcasts in his homeland half a world away. It was the crowning achievement for a nation that boasts more top-200 Scrabble players than any other country, including the U.K., Nigeria's former colonizer and one of the board game's legacy powers. "In other countries they see it as a game," said Mr. Jighere, now a borderline celebrity and talent scout for one of the world's few government-backed national programs.
You can find Lynda Woods Cleary playing Scrabble every Tuesday at a Panera in Princeton, NJ. Cleary, a 68-year-old retired financial consultant, has been playing every week for 20 years since founding the Princeton Scrabble Club in 1998. When I asked her if she's ever disappointed to draw certain tiles, she looked surprised, even hurt. "Oh no," she said with an Alabama twang. "I want each and every one."