In this version
of the board game GO you select if you want to play against the
computer or other human player:
If you want
to play against another person ( 2 players
) click on menu and select:
Black is :
Human Player (+ click on button "Settings")
White is :
Human Player (+ click on button "Settings")
In order to
play against the computer select Human player
for pices color, and other options select:
The computer plays fast without much "thinking". Recommended
The computer uses estadistic evaluation (heuristica) to define
the next move.
The computer selects the optimal move based on all the possible
ramifications of the game.
Enter the number of divisions for the size of board that you
Click on the place where you want to place your next
is to surround or to lock up one or several pieces of the opponent
and estrategically avoid to be surrounded.
Go pieces are black and white lens-shaped discs called stones. The
Go board can either be a flat table board or the more traditional
floor-board with legs (Go-ban). Either way, the board is simply
a grid of 19 x 19 lines, the pieces being placed upon the intersections
of the lines.
Go is a game
of territorial capture - the primary objective is to encircle as
much territory as possible. In doing so, opposing stones may be
captured and the winner is the player at the end with the greatest
amount of territory and captured stones.
The most essential terms to understand are "group" and
A group of stones
is any set of stones of the same colour that are connected orthogonally.
So three stones in a row along a line forms a group because every
stone sits orthogonally next to at least one other stone. However
2 stones next to each other diagonally are not connected in any
way and so simply form two groups of one stone each. If a third
stone were to be added to the two diagonal stones so that it sat
next to both of them, however, a group of three stones would be
formed. Groups can get quite large and convoluted but the principle
remains the same - if a stone lies orthogonally next to another
stone then both stones are part of the same group.
Any empty point
orthogonally adjacent to a group of stones is said to be a liberty
of that group. A single stone by itself in the middle of the board
therefore has 4 liberties, 1 in each of the 4 directions. A group
of 3 stones by itself in a line on the edge of the board has 5 liberties
- 1 at either end and 3 towards the middle of the board. And a group
of 8 stones set in a square by itself has 13 liberties - 12 around
the outside and 1 in the middle. But each stone laid by the opponent
next to a group reduces the number of liberties by 1. So a single
stone with opposing stones North, South and East of it has only
Go is not only
pleasing to the eye, the game itself is also beautifully aesthetic
in its simplicity. In fact, in essence there are really only 3 rules
to the game:
black, each player places stones on the board in turn.
When a stone is played so that it causes a group of opposing stones
to have no liberties, that group is captured.
A player cannot play a stone to a location if such a play would
cause a previous position to be repeated.
So a single stone is captured if the opponent places four stones
on the four orthogonal points surrounding it. And a group of 2 stones
on the edge of the board is captured by 4 enemy stones.
Eyes - the key
An important point to realise is that a group of 8 stones set in
a square is difficult to capture because if the opponent places
a stone in the middle of the group, under most circumstances, that
stone is immediately captured by the surrounding group. Consequently,
no player would ever normally make such a play. The unoccupied point
in the middle of the group is an example of an "eye".
An eye is any empty point that is surrounded orthogonally by pieces
of the same colour - always difficult for an opponent to capture.
However, eyes are not impossible to take - the group of 8 stones
can be captured by an opponent who first occupies the 12 surrounding
points. After this, the group of 8 stones is vulnerable - if the
player who owns it plays to the middle of the group, the group of
9 stones would be immediately captured having no remaining liberties.
And this is the only situation where it is legitimate for the opponent
to play a stone to the middle since in doing so, the last remaining
liberty of the group is eliminated and the group is captured. The
stone just played would be left surrounded by 4 liberties.
this is the key factor in Go defence - any group containing two
eyes is safe and can never be captured. This should be easy to understand
after a moments thought - in order to capture the group all liberties
must be eliminated and so both eyes would need to be occupied. But
since a stone played to either eye would immediately be captured,
it is impossible for both eyes to be occupied. QED.
eyes are useful and a group with 2 eyes is invulnerable.
"Ko" is a local situation in which a position can be repeated
indefinitely. For an example, lay a white stone on the edge of the
board and a black stone three points away from it also on the edge.
Lay another white stone diagonally next to the first white stone
in the direction of the black stone. Finish the pattern symmetrically
by laying a second black stone diagonally next to the first black
stone. Now play a white stone on the edge next to both black stones.
This situation is Ko. A black stone played to the remaining point
in the middle captures the white stone but the white player can
then play another white stone back to the same spot capturing the
black stone in the same way and putting the position back to how
it started. And so on. Of course, due to the third rule above, the
black player would not be allowed to do this immediately after the
capture of the black stone - at least one stone must be played elsewhere
before black could play otherwise the a previous position would
is another local situation. This term applies to an area into which
neither player dare play because to do so would cause the opponent
to capture territory or stones.
To have "Sente"
is to be in a position to make a move that will force the opponent
to take a counter-action. If a player with sente makes the play
in question and the opponent, instead of responding in the predicted
way, makes a different play with an even greater threat, the opponent
is said to have "assumed Sente".
Any group of
stones that is under threat of imminent capture i.e. having only
one liberty left is said to be in "Atari".
point is an empty point between territories. When there is a dame
point there is no benefit to either player. Dame points are left
alone until the end of the game and then ignored in scoring.
Go employs a simple and effective handicapping scheme. The weaker
player always plays black but also places an amount of stones onto
the board before the start of the game according to the amount of
the handicap. The board has nine highlighted intersections in a
square shape marked on the board called "star" points.
The requisite number of stones are placed the star points in the
1 stone handicap
- on a corner star point
2 stone handicap - on opposite corner star points
3 and 4 stone handicap - on 3 or 4 corner star points
5 stone handicap - 4 corner + 1 side star point
6 stone handicap - 4 corner + 2 opposing side star points
7 and 8 stone handicap - 4 corners + 3 or 4 side star points
9 stone handicap - all 9 star points.
Beginning the game in Go is both critical and very difficult to
do well. Players try to play stones far enough apart so that they
form the beginnings of territory encirclements but close enough
so that they can be linked up into groups should they come under
attack. Initial stones tend to be played near the corners - corners
are the easiest places to capture territory because they only have
to be surrounded on two sides. Good players will begin by positioning
stones seemingly at random across the board but in reality they
are staking their claims to particular areas. After this initial
period, local skirmishes and larger battles will form in areas of
contention. Players need to be able to comprehend and deal with
all the smaller conflicts while never becoming distracted from the
overall picture of the war.
Eventually, the players agree that no more stones can be played
since all territory is claimed and all local battles have been played
to their conclusion. Play continues until both players agree to
this. At this point the winner and the margin of victory is determined.
Essentially, each player scores the number of points of territory
plus the number of prisoners captured. The totals are unimportant
- it is the difference between them that is measured and it is customary
to calculate this in a special way.
stones on the board are moved around to form neater patterns, easier
for counting. Players do this by sliding stones from one place to
another taking care not to change the amounts of territory owned.
Some of the black stones will be moved to a different point within
black's territory so that the stone's new position reduces the territory
by one but the point freed up increases it by one to compensate.
White stones similarly. Once this repositioning has been done, all
the captured prisoners taken are laid down into enemy territory,
again in a neat way to make counting easy. This is done on the basis
that losing a point for a prisoner is equivalent to reducing by
one the number of points of territory held by the opponent.
Once the board
and prisoners have been consolidated in this fashion, the winner
and the margin of victory can be quickly determined by a count of
the simplified territories.
Since it is
generally recognised that black has an advantage by going first,
non-handicapped games are often decided as the best of two games
with players taking turns to play black. The margins of victory
are summed after both games have been completed to determine the