ICGA Journal - Volume 28, issue 1 - Journals

Abstract: A notion of union-connection in the game of Hex is introduced as a generalization of the well-known virtual connection. This is applied to obtain two easy-to-verify winning strategies in 7 × 7 Hex. The extensive use of union-connection along with some related techniques leads to a new proof for the solution of 8 × 8 Hex. It is a win for the first player (Black).

DOI: 10.3233/ICG-2005-28104

Citation: ICGA Journal, vol. 28, no. 1, pp. 3-12, 2005

Price: EUR 27.50

YET ANOTHER MASTERMIND STRATEGY

Authors: Kooi, Barteld

Article Type: Research Article

Abstract: Over the years many easily computable strategies for the game of Mastermind have been proposed. In this paper we present a new strategy (at least to our knowledge) that performs better than the well-known strategies: guess the code that has the highest number of possible answers. It is motivated and compared to four well-known strategies. Some empirical results are presented and discussed.

DOI: 10.3233/ICG-2005-28105

Citation: ICGA Journal, vol. 28, no. 1, pp. 13-20, 2005

Price: EUR 27.50

RANDOMISED EVALUATIONS IN SINGLE-AGENT SEARCH

Authors: Althöfer, Ingo | Heuser, Susanne

Article Type: Research Article

Abstract: Heuristic tree search is a widely and successfully used principle in game-playing programs. Following an old investigation by Beal and Smith (1994) and a recent study by Sadikov, Bratko, and Konononenko (2003), we discuss depth-t search with randomised evaluation functions: the heuristic leaf evaluations at depth t of the game tree are artificially randomised before backing them up. Our experiments were performed for single-agent search, namely in the sliding tile puzzle SlideThree (Troyka, 2001). We construct six evaluation functions of different playing strength and compare them to their randomised versions. Furthermore we also study the …perfect and the constant evaluation function and the dependence of the playing strength on the search depth. The main finding is that applying a random disturbance to the heuristic leaf values may considerably improve the playing strength of imperfect evaluation functions.3 Show more

DOI: 10.3233/ICG-2005-28106

Citation: ICGA Journal, vol. 28, no. 1, pp. 21-31, 2005

Price: EUR 27.50

SOLVING CHECKERS: FIRST RESULT

Authors: Schaeffer, Jonathan

Article Type: Research Article

Abstract: The game of checkers (8×8 draughts) has a search space of roughly 500 billion billion positions (5×l020 ). There are 174 three-move (or ply) openings in checkers. This paper reports that the much-feared White Doctor opening has been solved—it is a draw. This is the first checkers opening to have its perfect-play result determined. Roughly 50 openings need to be solved before the game-theoretic value of the initial position of the game can be determined. The only hurdle remaining to complete the goal of solving checkers is computing resources.

DOI: 10.3233/ICG-2005-28107

Citation: ICGA Journal, vol. 28, no. 1, pp. 32-36, 2005

Price: EUR 27.50