Bushka features a modified version of Fanorona's way of capture. Capture by withdrawal has been disposed of and capture by approach by a single piece is restricted to the actual piece contacted, rather than the whole line. This reduces the basic capture to a scenario of two men on three squares, just like Draughts, and in fact very similar:


draughts

bushka
Because of the similarity, the idea came to see how 'contact capture' would behave in the best available framework of rules and conventions: the one of International Draughts. Two of these are:

  1. A multiple capture must be completed before the captured pieces are removed.
  2. During a multiple capture a square may me visited more than once, but a piece may not be captured more than once.


draughts

bushka
In Draughts it is not possible to make a 180 degrees turn (2) but in Bushka you can.

In Bushka a capture cannot proceed in the same direction (1) but in Draughts you can.

Different implications, but very similar behaviour.


draughts

bushka
Of course the capturing pieces in both methods can change direction on any square.

Another implication to realize is that in Bushka a piece cannot reach the backrow in a capture, so there's no need for a rule regulating the event.
There are differences too. Draughts' initial position puts the forces much too close for comfort for Bushka. After a brief 9x11 period the game was reverted to a 10x10 board with fifteen men on the first three rows each. Quite modest in fact, but contact capture by nature requires four free rows between the forces to allow for different opening strategies.
More importantly: something was missing. Just putting a new monkey in the cage turned out a game not quite as inspiring in its combinations as Draughts itself.


linear capture before ...

... and after the move
The remedy was taken from its direct ancestor Fanorona and is called linear capture. But unlike Fanorona, the condition in Bushka is linear movement: moving a straight uninterrupted line of men one square forward as a whole, provided the square in front is vacant. If a moving line contacts a straight uninterrupted opposing line of men, the latter is captured as a whole.

Thus Bushka became the source of Draughts' style linear movement.

Rules
The rules mention men and kings. A king is a promoted man. If the difference doesn't matter, they may also mention pieces, for instance 'the number of pieces on the board'.

On the board there are squares and lines. These are always dark squares and oblique lines, like the 'e-line' or the '5-line'. A square is identified as the intersection of two lines. The 1- and 0-line each count but one square.
The five most distant squares from a player's point of view are called the back rank.

Initial positionThe diagram shows the board and the pieces in the initial position. There are two players, black and white. White begins. Players move - and must move - in turn.

Object
  • If a player has no legal move he loses the game. This may come about either by being eliminated or being blocked completely.

Movement
Capture has precedence over a non-capturing move. If the player to move has no capture to make, he has the following options:

  • Moving a man or a line of men.
  • Moving a king.

piece movementPiece movement
  • A man moves one square forwards along a line, provided it is vacant. If a man reaches the back rank, it is promoted to king. This marks the end of the move.
    A king moves any distance along an open line.

linear movementLinear movement
  • A line of men is an unbroken row of men of one color on a line. The shortest possible line of men consists of two men. A king is never part of a line of men. A line of men moves, as a whole, one square forwards along the line of squares it defines, provided the square in front is vacant. If it hits the back rank, only the front man is promoted. A line of men may not move backwards (though it may capture backwards).

In actual play not all men of a line of men are moved. One simply picks up the last man of the line of men one intends to move, and puts it in front. This may be any man of the line of men from the second to the last. In the diagram all white's initial options are displayed.

Capture
Capture is compulsory. In Bushka all capture is by contact. There are two distinct ways to do this:

  • Linear capture means capture with a line of men.
  • Piece capture means capture with a man or a king.
  • Linear capture precedes over piece capture, even if the latter is a majority capture!
    Within each principle, majority capture precedes.
  • If the player to move can make exactly one linear capture, he must do so. If he can make more than one, he must choose the capture that brings the maximum number of captured pieces. A king counts as one piece. If there is more than one way to meet this criterion, the player is free to choose.
  • If the player to move cannot make a linear capture, he must look for a piece capture. If he can make exactly one, he must do so. If he can make more than one, he must choose the capture that brings the maximum number of captured pieces. A king counts as one piece. If there is more than one way to meet this criterion, the player is free to choose.

Linear capture
A line of men makes only one movement in a turn! In a capture, this movement may be forwards or backwards. If the square in front of a line of men is vacant and the square beyond is occupied by an opponent's piece, the line of men captures by approaching one square, 'touching' the piece with its head.

  • If the piece is a king, it is therewith captured and removed in the same turn.
  • If the piece is a man that is the head of an opposing line of men on the same line, that entire line of men is therewith captured and removed. If it is not the head of an opposing line of men, only the man itself is captured.


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Since a line of men may capture both forwards and backwards, the expression 'the square in front' must be seen within the direction of the move. This one-liner illustrates the point.

Piece capture
Where a linear capture keeps a particular line, a piece capture may not. A piece may capture both forwards and backwards and may change direction as often as is required under the condition of majority capture.

The first condition for making a piece-capture is the absence of a linear capture. A man that is the head of a line of men in a particular direction can therefore never capture as a piece in that direction. Of course the man may be the head of a line of men in one direction, but not so in the perpendicular direction. The man is then called isolated in the latter direction.

  • A man can only start a capture in a direction in which it is isolated. Once the capture starts, the man remains isolated by definition for the rest of the turn.
  • If a man is isolated on a particular line, and next to it on that line is a vacant square followed by a square occupied by an opponent's piece, then the man captures the piece by making a one step approach onto the vacant square, contacting the piece. Note that a piece captures only a piece, not an entire line of men.
    If the man, now isolated by definition, can proceed in a similar way in another direction, including a 180 degrees turn, it must do so, taking care beforehand to establish the route that brings the maximum number of captured pieces. A king counts as one piece.
    If there is more than one way to meet this criterion, the player is free to choose.
  • A king is isolated by definition. It looks along open lines. If it sees, at any distance, an opponent's piece, then the king captures this piece by approaching onto the last vacant square before it, contacting the piece.
    If it can proceed in a similar way in another direction, including a 180 degrees turn, it must do so, taking care beforehand to establish the route that brings maximum number of captured pieces.
    If there is more than one way to meet this criterion, the player is free to choose.
  • After - and only after - a multiple capture has taken its complete course, the captured pieces are removed from play.
  • In the course of a multiple capture a piece may visit the same square more than once, but it may not capture the same piece more than once.


Draws
The game may end in a draw by 3-fold or mutual agreement.


Examples
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This position illustrates a seldom encountered detail in the rules: in the course of a capture, a piece may visit a cell more than once, but it may not capture a piece more than once.

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Three kings win against a lone one. here's an example. The first move forces black off the e-line because of fe4 followed by ge6 or vice versa, or on e97 immediately g67.

The second move prevents de9 because of ge3 followed by fe5.

  • d98 and d97 are followed by g38 and g37 respectively.
  • d92 is followed by 3.gd3-de2 4.fe5-e24x 5.de3

Problems
Here are some examples to get a preliminary impression of Bushka tactics. All problems: white to move and win.

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How I invented ... Bushka
Using the Bushka applet
External links