Anastomochess

Introduction

This article describes a project related to the chess game.

The purpose of the project is not a chess playing engine; it is a chess database and a front-end program to explore it (a dedicated web site).

Building the database

The building of the database should include the loading of MANY games (~10⁶ and more if possible).

The loaded games should include (besides the sequence of moves), the result and the name and elo rating of the players.

Each game will be processed so that the 20 (or more) first positions generated by the moves are stored in the database.

Anastomosis

In a tree (computing science or life science), the anastomosis is the reconnection of two streams that previously branched out.

In chess anastomosis is highly present, but poorly handled.

Indexing positions

In order to manage a large number of positions, a good indexing scheme is required. An original and performing scheme is documented here, and provides a way to index ans position on a bit set. The number of bits of between 78 and 113, depending on the complexity of the positions, but this is optimal in terms of compacity.

Database content

For each position in the database, the following fields should be present:

• the number of paths leading to that position (anastomosis factor)
• the various last moves leading to that position (and links to the corresponding previous positions)
• the various next moves played from that position, and for each of them
  • the number of time they were played
  • the average Elo rating of the players who chose them
  • the results of the games (white/draw/black)
  • an uncertainty measure for this position, using an entropic measure