Calculating Bridge Tournaments

Introduction

Bridge is primarily a card game, officially called 'Contract Bridge'.

This card game is most often played in a special form, called Duplicate. In this form, the same hands are being played at two or more tables. The results are compared, thereby achieving that it does not matter what cards you get, only how you play with what you got.

In order to achieve this, a number of people will combine to produce a 'Tournament'. The official Laws of Duplicate Contract Bridge make the distinction between two sorts of these people : The 'Sponsoring Organisation' and the 'Tournament Director'.

The Sponsoring Organisation will provide such arrangements as :

• Playing Quarters
• Equipment
• Conditions of Entry

The duties of the Tournament Director are more directly linked to the tournament itself, and can be subdivided in three parts :

• Before the tournament : establishing the 'Movement' (who plays whom)
• During the tournament : general direction, including administering the Law
• After the tournament : calculating the results

Although these three duties are quite different, no attempts are being made to attribute these duties to different people. At every level, all Tournament Directors are supposed to know all three aspects of these duties. It is in fact quite necessary that the person in charge of a tournament should know all three aspects of the duties that he faces.

No doubt some truly gifted in only one or two areas are thus prevented from attaining official status in their speciality, due to the fact that they are judged on their overall capabilities. Yet nothing prevents a qualified tournament director from seeking assistance from such a ‘specialist’.

The literature for the Tournament Director is varied :

• He will find several works on The Laws
• He is quite literally inundated with works on Movements
• The calculation is however mostly confined to the back of one or other of these works

In this guide, I will try to redress the balance, and show the different ways a Duplicate Bridge Tournament can be calculated. I have included several obscure ways of doing this (Chapter XIV.), but the main point of this work deals with the two main methods :

• 'MP'-type calculation :
  • Mitchell,
  • Mitchell-Neuberg and
  • Ascherman systems
• 'IMP'-type calculation :
  • Butler,
  • Bastille and
  • Cross-IMP systems

Of these six systems, two are my own inventions. They are nevertheless included out of merit (well, I would say that, wouldn't I - better judge for yourself)

The system called 'Mitchell' is the best-known of all, although the name will not be familiar. I have given the 'normal' system this name in recognition to its inventor, John Mitchell (who also invented the movement) in the 1880's.

The Mitchell-Neuberg system is furthermore composed of three separate ‘sub’-systems, which I will call Mitchell 2, 3 and 4 (to distinguish from the original Mitchell 1, which does not include the Neuberg formula). The Mitchell 2 and 3 systems are dealt with in the chapters titled ‘Mitchell-Neuberg’, the Mitchell 4 will be described starting from chapter

This work is divided into three parts :

• A general description of the six major systems shown;
• A description of the different problems encountered when scoring a tournament;
• A more detailed description of how the different systems cope with the problems.

Last Modified : 1996-06-27