Cooperation and competition of agents in the auction of computer bridge.

The auction in contract bridge is a game with incomplete information. This paper models the process as an interaction among agents with a hypothetical reasoning mechanism. The criterion for the action of each agent is defined as “maximizing gain by cooperating with the partner and minimizing loss by competing with the opponents.” An agent with the following characteristics is created. Based on the course of bidding, the hands of both sides are estimated by hypothetical reasoning. Then flexible bids are made in an effort to obtain the contract with the greatest gain or smallest loss of points. Experiments show that in a game with incomplete information, it is useful not only to send information to the partner, but also to disrupt information exchange by the opponents. The effect of ambiguity of information on the behavior of both sides is discussed. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(12): 76–86, 2003; Published online in Wiley InterScience (<URL>www.interscience.wiley.com</URL>). DOI 10.1002/ecjc.10144 [ABSTRACT FROM AUTHOR]