Copyright © 2011 Grant Cairns and Nhan Bao Ho. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
We reexamine Albert and Nowakowski's variation on
the game of Nim, called End-Nim, in which the players may only
remove coins from the leftmost or rightmost piles. We reformulate
Albert and Nowakowski's solution to this game. We examine its
misère version and a further variant where the winner is the player
who reduces the game to a single pile; we call this Loop-End-Nim.
We show that the three games, End-Nim, misère-End-Nim, and
Loop-End-Nim, all have the same losing positions, except for the
positions where all the piles are of equal size. We also give some
partial results concerning the higher Sprague-Grundy values of the
three games.