# The Gazette - November 2001

Edited by Peter Price

The views expressed in the Gazette do not necessarily reflect the policies or views of the BCA, nor those of the editor.

## A SEQUEL TO COLLISSON'S CONUNDRUM

Readers will recall that in the August issue, Francis Collisson posed the question of the possible number of moves confronting each player after each has completed ten moves of a game, and no material has been taken. This set me thinking and researching, and I am grateful to co-authors, Mike Fox and Richard James for permission to include the following extract from their enthralling book, "The Complete Chess Addict":

"In the starting array, white has a choice of 20 moves, and black a choice of 20 replies, making a total of 400 possible positions after one move by each side. After two moves by each side the number is 71,852. In 232 of these positions white will have the option of making an en passant capture, so, theoretically speaking, the number should be 72,084, which may be reached in about 200,000 different ways. After three moves the number of possible positions is somewhere over nine million. If you wanted to reach every possible position after four moves, taking one minute each one, it would take you a matter of 600,000 years."

As an ordinary mortal, I have to concentrate on making even one move when that clock is ticking!

Editor.