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Liberty - introductory
Path: GiveMeLiberties   · Prev:   · Next: Liberty
  Difficulty: Introductory   Keywords: Tactics

This page explains some very basic points about the notion of liberty (sometimes called 'freedom' or 'breathing space') of stones in go.

[Diagram]
In the same chain

Two stones of the same colour that are joined together along the lines stand or fall together - the nature of the rule of capture means that either both are captured at the same time, or neither is taken. Here BC and BS will have the same fate.



Liberties belong to a whole chain (connected unit) of stones joined together by lines connecting neighbouring stones. (This idea is formally defined if required - see chain.)

Any chain on the board has at least some liberties - empty points next to the chain, where that means they are adjacent to some stone in the chain along one of the lines.

[Diagram]
Nine liberties

Here Black's chain has the nine liberties marked with circles. Diagonal adjacency - the relation of BC to the point marked with a square - doesn't give rise to liberties.



If you fill in all the liberties of an opponent's chain with your own stones, you capture it. Capture is one of the fundamental ideas of the game, the other being territory. The capturing page surveys many of the implications.


In every legal position, each chain on the board does have a liberty. At the end of each turn a legal position must remain on the board. The updating of the board at the end of Black's turn is to remove all white chains without liberties; and equally at the end of White's turn any black chains without liberties are removed. Only mistakes by the players can account for chains without liberties remaining between turns.

A chain with one liberty remaining is said to be in atari. The opponent can capture it next turn (with the exception only of the ko rule). Shortage of liberties is a term applied to all tactical situations where having too few liberties causes one player inconvenience or danger. There are many ways in which one can run short of liberties and later regret that. A common mistake is to fill in one's own liberties for no very good reason (don't take away your own liberties). The empty triangle is taught as a prime cause of shortage of liberties.

You don't necessarily try to capture stones by filling in liberties: this only works really well for chains of two and three liberties. A range of techniques needs to be acquired. Indirect 'fencing in' works better for larger numbers (the principle of the net), and certainly is less dangerous than vigorous, indiscriminate chasing (the principle of the ladder).


Capture has a couple of senses, as these comments reveal: successfully shut in stones, which can't survive with two eyes (or seki), are referred to as dead; and in those cases their number of liberties may not matter. When stones have two eyes they are safe, and you could say that their number of liberties has also ceased to matter. Still, shortage of liberties has many forms relating even to apparently safe groups.

Perhaps this makes plausible that liberty, too, has a further and less elementary sense. Read more on the liberty page, to begin to understand how to count liberties when they matter most. In capturing races there are many deceptive effects, as one tries to assess whole groups, and the time factor involved in taking them off the board (in particular so-called approach moves). In a phrase like 'trying to gain liberties', you can be sure that this does mean 'trying to postpone capture', by whatever tactics can be found.

Charles Matthews


Discussion moved to Liberty - Discussion.



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This is a copy of the living page "Liberty - introductory" at Sensei's Library.
(OC) 2004 the Authors, published under the OpenContent License V1.0.