ICGA Journal - Volume 18, issue 3 - Journals

Show:

results per page

Bright and Beautiful, Great and Small

Authors: Herschberg, Bob | van den Herik, Jaap

Article Type: Editorial

DOI: 10.3233/ICG-1995-18301

Citation: ICGA Journal, vol. 18, no. 3, pp. 133-134, 1995

Get PDF

Controlled Conspiracy-Number Search

Authors: Lorenz, Ulf | Rottmann, Valentin | Feldmann, Rainer | Mysliwietz, Peter

Article Type: Research Article

Abstract: We present a new conspiracy-number search algorithm (CNS), called Controlled Conspiracy-Number Search (CCNS). The basic steps of any CNS algorithm, the selection, the expansion, and the backup of results have been modified compared to other CNS algorithms. The selection is done by assigning demands, so called en targets, on the nodes of a game subtree in a top-down fashion. Doing so, a set of leaves is selected in a single action. An expansion is used to check whether a leaf node can fulfil the demands imposed upon it in terms of conspiracy number. A backup subalgorithm uses heuristic information gained …from the expansion step in order to prepare the game subtree for the next selection phase. We have found our algorithm to be stronger than the a-p algorithm in tactical positions. This has been shown by comparison them on a recognized set of test positions. It is able to play reasonably even in non-tactical positions, as shown on the 4th International Paderborn Computer-Chess Championship, where ULYSSES CCN, a program based on the CCNS algorithm, participated in a complete tournament with creditable results. Prospects are that, every selection step selecting a set of leaves for expansion, the algorithm will prove well-suited to parallelization. Show more

DOI: 10.3233/ICG-1995-18302

Citation: ICGA Journal, vol. 18, no. 3, pp. 135-147, 1995

Price: EUR 27.50

Combining Knowledge and Search to Yield Infallible Endgame Programs

Authors: Barth, W.

Article Type: Research Article

Abstract: A provably correct program for the competition of passed Pawns in the KPKP endgame has been developed, using a method described due to Barth and Barth (1992). The method combines the application of strict rules with α -β search. The rules cover a large part of the positions of the endgame. For each such position they define an interval guaranteed to contain the true value. An α -β search finds the values for all positions not covered and removes uncertainties left by too wide intervals in rule-valued positions. Thus, the method yields a correct evaluation for every position …and, furthermore, the rules governing the position or its successors provide some tutorial insight to the user about the reasons behind the evaluations. Moreover, automatic validation assures that mistakes in the rules will be discovered and then can be eliminated in dialogue. Only a few simple rules are essential to the KPKP algorithm, all of which are well-known to skilful chess-players. Some of them are almost trivial, yet they have to be formulated with cautious precision and to be cast into an algorithmic format. Surprising oddities come to light in the process. The behaviour of the program has been tested by solving many studies and by analyzing some game positions discussed in the literature. Show more

DOI: 10.3233/ICG-1995-18303

Citation: ICGA Journal, vol. 18, no. 3, pp. 148-159, 1995

Price: EUR 27.50