Nine Men's Morris Problem
Wednesday, 17th September 2014
This is the first in an occasional series of problems for the game of nine men's morris. Feel free to leave your proposed solution in the comments, or on one of this site's social media accounts (see buttons in the footer), or alternatively, by email.
In this puzzle it is white's turn to move. The notation indicates the first and last point numbers on each row. Notice the running mill on points 4-6 and 13-15 which has reduced black to four pieces. From this position, only one move will guarantee white a victory in three turns: what is it?
Comments
Is it 22 to 10?
Wonderful site. I'll pick up your book as soon as I get some of that--what-do-you-call-it?--oh yeah, disposable income.
Cheers, Nick
Nick Slosser - 08:11, 24/06/2015
There are two different first moves to this three turn victory.
1. 22 -10 19 - 11 2. 6 - 14 f23 - 6 3. 4 - 11
1. 4 -11 2 - 1 {alternatively 23 - 20} 2. 22 - 10x19 f23 - 4 {alternatively f20 - 4} 3. 6 - 14x4
4 - 11 is a superior move for white during the normal course of the game, since black is blocked out of a mill. However, flying makes both 22 - 10 and 4 - 11 equal moves during the endgame. Endgame victories generally requires two open mills and the opponent to have no partial mills. Black must move 19 or 23 to 20. 23 - 20 is better, since the move obstructs white a little. White must remove 20 (or 19, 23) to avoid a mill from black. In addition to the two open mills white needs a third mill to remove black's fourth piece.
Brent Baldwin - 20:58, 26/06/2015