Fanorona
History of Fanorona
Fanorona is the national game of Madagascar and was derived from the game Alquerque which might be over 3000 years old. Fanorona has three standard versions: Fanoron-Telo, Fanoron-Dimyand, and Fanoron-Tsivy. The difference between these variants is the size of board played on. Fanoron-Telo is played on a 3×3 board and the difficulty of this game can be compared to the game of tic-tac-toe. Fanoron-Dimyand is played on a 5×5 board and Fanoron-Tsivy is played on a 5×9 board. We will call Fanoron-Tsivy from now on Fanorona since the Fanoron-Tsivy variant is the widest-known variant.
There exist some legendary stories about Fanorona and one of them involves a King called Ralombo. Due to this story the program used for solving Fanorona was called “KING RALOMBO“. King Ralomba became sick and decided that it was time for one of his sons to inherit his kingdom. The king did not want to split up his kingdom so he decided that the first son which arrived at the castle was the most devoted one and therefore should become the next king. So the king sent out messengers calling for his sons. The elder son was playing Fanorona by the time the messenger arrived. He did arrive at a very difficult situation called telo noho dimy which is a 3 pieces against 5 pieces situation. He was so concentrated on how he could win this situation that he did send the messenger away so that he could concentrate on the game. By the time he arrived at the castle of the King the younger son had inherited the throne.
Rules of Fanorona
Board
FanoRona is played on a 5×9 board and it is played along the lines and on its intersections just as Go. A line represents the way along which a stone can move during the game. There are strong and weak points (intersections). On a weak point it is only possible to move a stone horizontally and vertically, while on a strong point it also is possible to move stones diagonally. A stone can only move from one point to another at a time. Each player has 22 stones at the start position as shown in Figure 2.1. The player to start is White, as may be expected from a western game.
Capturing
Players are allowed to play a move alternatively. Even if a move consists of multiple movements of one single stone we will still denote it as a single move. Capturing stones of the opponent can be done in two different ways, either by approach or by withdrawal. An approach is the movement of the capturing stone to an adjacent point of an opponent stone if the opponent’s stone is placed on the extension of the movement line of the capturing stone. A withdrawal is the movement away from the opponent’s stone if the capturing stone is placed on an adjacent point of the opponent’s stone and if the opponent’s stone is placed on the extension of the movement line of the capturing stone. When an opponent’s stone is captured by approach or by withdrawal, all opponent stones in line behind that stone (as long as there is no interruption by an empty point or an own stone) are captured too.
Figure 2.2 shows how the capturing mechanism works. In the situation shown in Figure 2.2 White can capture Black’s stone on d2 by moving his white stone from b2 to c2. With this move also Black’s on e2 will be captured. g2 will not be captured since there is no black stone on f2. This was a capturing by approach since White moved his stone towards Black’s stone on d2. White can also capture by withdrawal if he moves his white stone from f4 to e4 since he is moving away from Black’s stone on g4. i4 will not be captured since there is a white stone disrupting the line at h4.
White cannot capture c4 with f4 since for a capturing move the own stone has to be next to the one captured after this move and f4 is too far away to capture c4. In order to allow a capturing the capturing stone has to be moved to an adjacent point next to the captured stone if it is approached. If a capturing is done by withdrawal then the capturing stone has to start at an adjacent point next to the captured stone and move away from it.
White also cannot capture c4 with b2 since c4 is not on the extension of a movement line from b2. Only stones can be captured which are located in the extension of the movement line of the capturing stone. Thus capturing “around a corner” is not allowed.
For describing a move we will define the following notation: a1-b2A means that the stone on a1 will move to b2 and approaches (A) the stone on c3. For a withdrawal the letter “W” is used. If a stone is moved without capturing opponent stones then no letter “A” or “W” will be used. Like Checkers it is allowed to keep capturing with the same stone as long as possible. Figure 2.2 shows that White can capture c4 with the move: b2-c2A-c3A. A player must choose a capturing move above a non-capturing move but a player is free to stop with capturing after any number of opponent stones are captured. In Figure 2.2 White is allowed to stop early and only play b2-c2A. A move where no stones are captured is called a paika move. Thus White is not allowed to play the paika move b2-b1 here since capturing is possible.
There are three more rules concerning capturing stones. The first is that it is not allowed to capture by approach and withdrawal at the same time. This is the case at the start position shown in Figure 2.1 where White could play d3-e3 as an approach or a withdrawal. In such a situation the player has to choose if the current move is an approach or a withdrawal. The second rule is that it is not allowed to make a capturing move in the same direction as the capturing move directly before. We illustrate this rule by referring to Figure 2.2. White is not allowed to play: f4-e4W-d4A since his stone would move two times in a row in the same direction. A player is allowed to play a capturing sequence with two times the same direction if a capturing with another direction is done in between them.
The last movement direction of the capturing in the turn before (i.e., before the previous opponent move) does not influence allowed capturing directions in the current turn. The last rule is that the current capturing stone is not allowed to arrive at the same point twice during a capturing sequence. If in Figure 2.2 a black stone would be on g5 then White is not allowed to play f4-e4W-e3A-f4A because of this rule.
End of the game
The player who first captures all opponent stones wins the game. There exist draw situations in FanoRona and both players can call it a draw if both do not see an opportunity to win. Such a draw situation is detectable in Figure 2.3 with White to move. White cannot move his stone in the middle or he will lose the game. The tactic for the black player is to stay always on the other side of White’s moving stone in order to achieve a draw.
