GIB

GIB is the world's first expert-level computer bridge player. It has received a great deal of press as a result of its participation in the Par Contest at the 1998 World Bridge Championships, which were held in Lille, France. In an invitational field consisting of 34 of the world's best card players and GIB, GIB finished 12th. Hands in which GIB has outplayed world-class human players are also the subject of a series of articles in the Dutch bridge magazine IMP.

GIB is written in C and is based on an extremely fast double dummy solver. The principal technique used to construct the double dummy solver is Ginsberg's partition search; the single dummy bridge player is built using Monte Carlo sampling techniques. GIB is also available as a product.

CIRL

GIB was developed in part at CIRL. The University of Oregon receives a commission on sales of the program.

Pointers

GIB: Steps Toward an Expert-Level Bridge-Playing Program: This paper describes GIB, the first bridge-playing program to approach the level of a human expert. We give a basic overview of the algorithms used, describe their strengths and weaknesses, and present the results of experiments comparing GIB to both human opponents and other programs. Written by Matt Ginsberg and to be submitted to IJCAI in 1999. Compressed postscript document.
Partition Search: We introduce a new form of game search called partition search that incorporates dependency analysis, allowing substantial reductions in the portion of the tree that needs to be expanded. Both theoretical results and experimental data are presented. For the game of bridge, partition search provides approximately as much of an improvement over existing methods as alpha-beta pruning provides over minimax. Written by Matt Ginsberg and appeared in Proc. AAAI in 1997. Compressed postscript document.
How Computers Will Play Bridge: This article describes the likely use of a fast double dummy search engine (such as the one in GIB) to unseat humans as the world bridge champions. The Monte Carlo sampling idea used by GIB is discussed, along with possible impact on bidding and other areas of the game. Written by Matt Ginsberg and appeared in The Bridge World in 1996. Compressed postscript document.
On the Law of Total Tricks: The "Law of Total Tricks" in bridge says that the two sides, when playing in their longest suits, can take between them as many tricks as they have trumps. Is this really a law, or just a vague rule of thumb? This article gives the answer. Written by Matt Ginsberg and appeared in The Bridge World in 1996. Compressed postscript document.
Techniques used:
Partition Search
Application area:
Bridge

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