In a game of Go, how can you tell whether stones are "alive" or "dead"?

Question

I'm learning to play the ancient strategy game go, and it's enthralling. But I'm left puzzled by the problem of how to work out whether stones are alive or dead, particularly at the end of a game.

At the end of the game, your opponent's 'dead' stones count as yours, and score you points. (I think they might score you points for both the territory they occupy, & the stone itself). So it's really important to work out which stones are dead.

Anybody got a comprehensive way of determining this?

Answer 1

The more you play, the easier it will become to see when stones are dead. A group is dead when it has no possible way to make two eyes, no matter where it moves.

An eye is a space your opponent can't move in, because it would be instantly captured (or be marked dead. and eye can have two or more spaces as well). However, if you only have one eye, if you opponent completely surrounds your group, he can then move in your eye space, and your group will be captured. With two eyes, that would be impossible. Even if he has every other liberty filled in, his stone can still not make a suicide move. So he will not be able to play the stone in your eye to capture your group.

When the game's played out, it's not usually necessary to specifically contrive two eyes. If you are surrounding a lot of territory, you have the *potential* to make two eyes, and so your group will be alive. Dead groups are ones that have no space for eyes.

In an average game, these are the types of dead 'groups' you will find at the end: single or small groups of stones that are in your opponent's territory, failed invasions (when you try to take a chunk of their territory and fail), any group that your opponent has completely surrounded (they don't need to capture it for it to be dead).

At the end of the game (in Japanese scoring, the kind you'll play on most go servers), both you and your opponent take all the dead stones off the board, and they are counted as captured stones. You also count the spaces that the captured stones were on as territory, the same as if you had taken away all liberties and captured them.

This site explains it more, with a few diagrams and an applet that will let you try making eyes for yourself. It's the best go tutorial out there:

http://playgo.to/interactive/

Lessons about eyes start from the 11th lesson, use the index on the left side to get there. You might want to look through the whole tutorial if you're new to the game, though.

Good luck, enjoy playing go :-)

Answer 2

When your opponents stones are completely surrounded they are dead

Answer 3

The easy answer for determining territory control (and the stones in that area for scoring) is if the game were to play out until every spot was filled would you control that territory.

As in there is no way for the other person to capture any of that territory.

There's also two kinds of scoring, japanese and chinese, one only counts the territory and the other counts stones and territory. I forget which is which.

http://gobase.org/studying/rules/ikeda/?...

That shows a pretty good picture for scoring and showing how if the game kept going what would take place and why you control that territory. As I mentioned above for the easy answer.

http://gobase.org/studying/rules/ikeda/

There's a whole section of links showing different end game positions and explaining how you would score them.

Go is a great game. Hope all that helps and enjoy playing!

Answer 4

Try pouring cold water on them, or if that doesnt work, break out the defibralator.