Here are two examples of finished games. The game is over when all the empty dots are surrounded by either player. At the end of the game, neither player receives points, as the empty spaces are not surrounded by either side. If both players succeed, the game is over and the score is counted. At the end of the game, the captured stones are placed in the opponent`s territory to reduce the score. The player who controls the most territory (points) at the end of the game wins the game. If a group has only one freedom, we say that this group is in the Atari, which means that it can be conquered in the next round. If black plays a flap, white can capture and delete the black group. In Go, creating enough eye space for your groups and preventing your opponent from making eyes is a key element. When a player places a stone, it (or the group they are connected to) must always have freedom. Empty spaces next to a stone are called freedoms. A single stone has four freedoms.
Players can capture an opponent`s stone (or group of stones) by placing a stone on all the stone`s freedoms (group). In diagram 6, there is still a freedom and black must first fill it. A stone does not move after playing, unless it is captured as a prisoner and removed from the board. To catch a group, all freedoms (tactile passages) must be filled with stones. But the group must not only be surrounded from the outside, but also the empty adjacent spaces within the group must be filled, because these are also freedoms. In diagram 7, the single empty space in the white group forms an eye. For a group to stay alive, it must contain at least two separate rooms (eyes). In Figure 4, white has 34 points and black 31 points. Note that placing a stone in an area you have already surrounded will reduce your score by one point. In diagram 1, the stones form 9 points of the territory. In diagram 8, Blacks can place a stone on the empty space and now all the white stones are captured.
A single empty space in a group of stones is called an eye. Then, the captured stone or group is removed from the board and kept by the player who captured it. Stones of the same color at adjacent intersections are connected to each other and form a group. When placing a stone, count its captivities first before it has freedoms. When white plays, black can fully capture the white group. At any time, a player can pass (not make a move), because placing a stone in a fenced area will cost him a point. This can be repeated endlessly and this situation is called « ko ». The connection can be horizontal or vertical, but not diagonally, because the connection follows the lines.
To avoid such situations, there is another rule: if black catches as in diagram 11, white can not immediately catch again, but must wait for at least one movement. Look at Chart 14 again. When White plays, the whole group is captured. When Black plays, White captures 4 black stones and gets 4 points. Now white can place a stone in the eye of the black group (diagram 13) and this will capture the black stone. If we remove the black stone, we have diagram 10 again. When two or more stones are connected, the group shares their freedoms. Now black tries to prevent the white from making two eyes and laying a stone (diagram 17), but white can place stone 4, making it impossible for black to capture the white group. In diagram 5, black can remove all three white stones because white stones have no freedoms (escapes). They are completely surrounded. So every player who plays loses the game in that area, so no player should make a move in it.
A movement is made by placing a stone on an unoccupied intersection. The player with the black stones makes the first move. After that, the white and black players take turns to make their moves. In diagram 10, black can put a stone in the white eye. As a result, the white stone is captured and it is now removed (diagram 12). Groups with two eyes cannot be detected because these eyes cannot be filled. The territory are empty spaces completely bordered and surrounded by stones of the same color. Note: When White was still free from the outside, this move could not be played because it is illegal to place a stone where it is caught (suicide). This means that a trapped stone can be seen as two points (1 for empty space and 1 for point reduction at the end). If we had to put a stone in one eye, then the group would still stay because it still has a freedom (the second eye).
We cannot place this stone because it would be suicide.