THE TWO ROOKS.
(
Puzzle Games.)
This is a puzzle game for two players. Each player has a single rook.
The first player places his rook on any square of the board that he may
choose to select, and then the second player does the same. They now
play in turn, the point of each play being to capture the opponent's
rook. But in this game you cannot play through a line of attack without
being captured. That is to say, if in the diagram it is Black's turn to
play, he cannot move his rook to his king's knight's square, or to his
king's rook's square, because he would enter the "line of fire" when
passing his king's bishop's square. For the same reason he cannot move
to his queen's rook's seventh or eighth squares. Now, the game can never
end in a draw. Sooner or later one of the rooks must fall, unless, of
course, both players commit the absurdity of not trying to win. The
trick of winning is ridiculously simple when you know it. Can you solve
the puzzle?
Answer:
The second player can always win, but to ensure his doing so he must
always place his rook, at the start and on every subsequent move, on the
same diagonal as his opponent's rook. He can then force his opponent
into a corner and win. Supposing the diagram to represent the positions
of the rooks at the start, then, if Black played first, White might have
placed his rook at A and won next move. Any square on that diagonal from
A to H will win, but the best play is always to restrict the moves of
the opposing rook as much as possible. If White played first, then Black
should have placed his rook at B (F would not be so good, as it gives
White more scope); then if White goes to C, Black moves to D; White to
E, Black to F; White to G, Black to C; White to H, Black to I; and Black
must win next move. If at any time Black had failed to move on to the
same diagonal as White, then White could take Black's diagonal and win.
r: black rook
R: white rook
+-+-+-+-+-+-+-+-+
|r| | | | | | | |
+-+-+-+-+-+-+-+-+
| |A| | | | | | |
+-+-+-+-+-+-+-+-+
| | | | | | | | |
+-+-+-+-+-+-+-+-+
| | | | | | | | |
+-+-+-+-+-+-+-+-+
| | | | |B|D|F| |
+-+-+-+-+-+-+-+-+
| | | | | |R|C|E|
+-+-+-+-+-+-+-+-+
| | | | | | |I|G|
+-+-+-+-+-+-+-+-+
| | | | | | | |H|
+-+-+-+-+-+-+-+-+
THE TWO ROOKS.
