Shatranj Problem, February 2015
Wednesday, 4th February 2015
Regular readers of this blog might remember the Shatranj problems I posted on a monthly basis last year. I've decided to start posting them again, despite the fact that some of them have mistakes, as they're an interesting retrospective on chess history.
A Reminder of the Rules of Shatranj
This is a brief reminder, for chess players, about how shatranj, or mediaeval chess, differs from the modern game.
The king, rook and knight move as the modern pieces do. The pawn only ever moves one step forward, never two. The bishop moves exactly two squares diagonally, and can jump over a piece in the way. The queen moves diagonally to an adjacent square, much like a draughts king.
Castling and en-passant moves are unknown. A pawn always promotes to a queen. Stalemate is a loss for the trapped player, and if one side is reduced to only a king then that player has lost the game.
The diagram shows the full setup of the pieces, and illustrates the symbols used for each of the pieces in the mediaeval game. For a full discussion of the game, including a full set of rules, see the Shatranj page.
These problems are said to be authored by mediaeval chess masters al-Adli and as-Suli, and were recorded in various manuscripts from between A.D. 1140 and 1370. They are given in H. J. R. Murray's 1913 book A History of Chess, from which I have taken them.
This month's problem is illustrated here. It is black's turn: what sequence of moves will force a black win? There are two solutions, each with a minor variation. I'll post both of these in a month's time, so keep an eye on this blog!