· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Strategy There are many different solutions to the standard problem, and one notation used to describe them assigns letters to the holes (although numbers may also be used): English European a b c a b c d e f y d e f z g h i j k l m g h i j k l m n o p x P O N n o p x P O N M L K J I H G M L K J I H G F E D Z F E D Y C B A C B A This mirror image notation is used, amongst other reasons, since on the European board, one set of alternative games is to start with a hole at some position and to end with a single peg in its mirrored position. On the English board the equivalent alternative games are to start with a hole and end with a peg at the same position. There is no solution to the European board with the initial hole centrally located, if only orthogonal moves are permitted. This is easily seen as follows, by an argument from Hans Zantema. Divide the positions of the board into A, B and C positions as follows: A B C A B C A B A B C A B C A B C A B C A B C A B C A B C B C A B C A B C Initially with only the central position free, the number of covered A positions is 12, the number of covered B positions is 12, and also the number of covered C positions is 12. After every move the number of covered A positions increases or decreases by one, and the same for the number of covered B positions and the number of covered C positions. Hence after an even number of moves all these three numbers are even, and after an odd number of moves all these three numbers are odd. Hence a final position with only one peg cannot be reached,