GO is one of the oldest known games.
Probably it was invented 4000 years ago in China, where the first Go book was written to. In Japain, GO was first introduced in 735 BC by the emperor Shonu. First it was played only by the higher social ranks. In 1603, by the time of Shogun Iyeyasu, the first Go academy was founded and functioned until 1868 (when the last Shogun died).
In the XVII - XIX century, GO become the favorit game of the samurais. In this period also appear many legendes and anecdotes about the game. Between 1868 and 1880 the game fall into oblivion, but after 1880 it was brought to Europe and America.
Since then the number of Go players is raising constantly in the whole world.
"Masters are recognized as what they can do with little things," says an old Chinese proverb.
This is good for the game of Go.
The board (Goban)
The Go-board, also called the goban is aproximatly a square of (45x41 cm), colored in orange to light brown and is covered by a grid of 19x19 lines. One square of the grid is 22x24 mm (the color and the dimensions of the grid are chosen so that the eye of the player didn't get tired when he watch the game). The stones are placed at the intersections of the grid.
The stones, (181 black and 180 white, because black startes the game he has one more stone then white) are lense-shape with a approximated diameter of 22 mm and a thickens of 5 - 12 mm. They all have the same value in game, and once put on the board they are not moved.
Today most of the stones are made of plastic, but traditional materials are sea shell or marble.
A zone limited by stones of the same color and/or the edge of the board is called territory . The goal of the game is to have the most territory. (in the image black has 8 points)
The intersections of the grid near a stone are called liberties .
In the middle of the board a stone has 4 liberties, at the edge 3, in the corner 2. The liberties of a group of stones are counted together. (see picture below)
If a stone, or a group of stones remaines without liberties, the stone/group will be considered prisoner and will be removed from the board. This operation is called capture.
The situation of a group or a stone with only one libertie is called atari.
A move that eliminates the last libertie from its own group, is called suicide Suicide is forbidden in GO. (white can't play at the red marked intersection).
A move that is followed by a capture is not suicide. (black can play at the red marked intersection).
Dead or alive
Groups with 2 inner liberties (so called eyes ) can't be captured, so he is alive. In order to capture the group, black must play 2 stones at the same time ore must commit suicide. Both actions are forbidden.
Groups without the possibility to get 2 eyes are dead. Dead groups can stay on the board until the end of the game, when they are removed. In some situations a dead group can revived So be careful with dead groups!
The special situation, when a stone, after capturing a stone of the opponent, remains in atari, and can be captured in the next move is called Ko.
To avoid repetition of the same situation over and over, it is permitted to recapture a stone in Ko, only after a move elsewere on the board. At the end of the game all Ko must be closed. (often the life of a group depends on a Ko!).
There is one strange situation in Go when a group can't be captured but without having 2 eyes. This situation is called Seki. In seki 2 group share 2 internal liberties. The player who move first will lose the group.
During a game of GO it is important to anticipate how a situation will develop. A little trick is to memorize some possible configurations of the stones and figure it out how it will evolve during a possible game.
Groups with 3 liberties
A group with 3 liberties has only one possible form. The red marked intersection is the critical point. If black is playing there, his group will live.
Groups with 4 liberties
4 liberties are a greater chance to live.
In the form of a "L" the group with 4 liberties will live regardless how will play next.
The configuration from above is not so great. If black can't play at the marked point, he will die.
One configuration to avoid is:
The only chance to live is seki!
Groups with 5 liberties
In the best cases there are 3 vital points.
But there are possible configurations with only 2 vital points. or with only one!
Groups with 6 or more liberties
This problem can be reduced to one of the already discussed problems.