Lessons in the Fundamentals: Atari (当たり)

Dia.1 - Liberties

When a player places a stone on the board, and assuming for the sake of simplicity that the board is empty, the newly placed stone has four liberties. In the picture above, each liberty is marked with a triangle. During the game, each player may capture a stone by filling all the adjacent intersections, thusly, capturing the stone. A stone that stands alone in an intersection may be compared to a fugitive standing at an intersection of a city. The man can see four streets. He remains free as long as one of those intersections is open for him to flee. But if all of them are blocked by those intent on capturing you, then you have no choice but surrendering. The same applies to the lone stone standing on the board. If you allow the black stone to be surrounded, it will run short of liberties, and be captured by your opponent.

Dia.2 - Atari

When a stone has only one vacant liberty, it is in atari. Atari means that under the current circumstances, this specific stone may be captured in the opponent's next turn.

Dia.3 - Capture

When the vacant point is filled, the stone is captured and removed from the board. White gains one point of territory and one point due to the capture of the black stone. White scores two points with the capture of the black stone.

Dia.4 - Liberties on the edge of the board

Because the edge acts as a natural barrier, when a single stone stands at the edge of the board, it has 3 liberties. On the corner, the stone is restrained by two edges, and has only 2 liberties.

Dia.5 - Liberties at the corner

Liberties are the most fundamental aspect of the game of Go. Remember to always count your liberties, and play accordingly, lest your stones are captured, thus providing your opponent with a valuable advantage.