Torbjörn Lindelöf

Bridge and the COBRA bidding system
Mostly for addicts

I am not a great bridge player, not even a good one by national standards. The reason I mention Bridge is that I have written a book, a widely appreciated study of my own, on the art and technique of bidding bridge hands.

Bridge bidding is an activity which requires skill. I have developed a bidding system, called COBRA (an acronym for Computer Oriented BRidge Analysis), published in 1983 by Victor Gollancz, London under the title: The Computer-Designed Bidding System COBRA.

COBRA was developed with the aid of main frame computers, using a technique for studying the trick-winning ability of various cards and combinations of cards, as a function of a number of suggested properties of the whole hand. This study eventually formed the basis for a highly successful hand evaluation method, around which it was comparatively easy to build a complete bidding system. COBRA has few really innovative features, except that it performs at a level of skill which is unusual, even among international masters.

Its strength lies in a strong relationship between bidding rules and hand evaluation as the auction proceeds. The human user of COBRA is not required to take any action whatsoever during the auction except to "calculate" the next bid, just as a computer will perform this menial task.

To be a perfect COBRA user one has to devote quite some time to practice and study. The system is based on a set of very well defined concepts, which have to be understood before one can undertake to use the COBRA Hand Evaluation method, and the bidding rules.

The system is thought to be simple enough, however, for humans to learn. Experience has shown that already the strict application of a proper subset of the COBRA system is often enough to make a "palooka" bid like a master. Experience has also shown that many bridge players cannot believe that a computer could possibly know the right bid in every situation. After having bid something else they often discover that it would have been better to bid just as COBRA dictated!

The original COBRA book is out of print. However, I can send you a pdf-file (you must have Acrobat Reader 4.0 or later) of the around 120 pages COBRA description. To cover cost of distribution and assembly I ask for the equivalent of US $15 in US, Swiss or Swedish banknotes. This also makes you a member of the COBRA Friends informal association, which simply means that you will receive notes from other COBRA users, collected over time.

To get a flair for the book you may also download two key chapters of the book, Concepts and Definitions, and Hand Evaluation where the unique COBRA hand evaluation method is described.

Torbjörn Lindelöf
COBRA Lab
Storgatan 7
S-582 23 Linköping
Sweden

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© 1999, Torbjörn Lindelöf, Linköping, Sweden