Meaningful Stones: Life Lessons in the Game of Go

The video covered solid connections, diagonal connections, and the one-space jump. There are even more efficient ways to expand, but they are riskier. Perhaps the most common is the knight’s move. The knight’s move is two steps in one direction and one step in another, like a knight moves in chess. It stretches a little farther than a one-space jump but it is easier for your opponent to separate, or cut, the two stones.

Here’s one possible sequence that shows how white can cut the black knight’s move into two separate groups.

Unless black can capture one of white’s cutting stones, the two black groups will remain separated. Of course, the two white stones are also cut, so what we really have here is the start of a fight! Black has to be aware of this possiblity, and white will have to evaluate whether the fight helps them before attempting the cut. The knight’s move is especially strong near the edges of the board, where one of the cutting stones will be in danger of being run into the edge of the board and captured.

The diagonal jump is another loose connection, stretching a bit farther and a little easier to cut. The diagonal jump is called hazama tobi in Japanese, and is sometimes called the elephant jump because it reflects how the elephant piece moves in Chinese chess.

You can see how white could keep these two black stones from connecting by placing a stone right in the middle. This will, of course, lead to a complicated fight!

Jumping any farther than this is too loose to consider a true connection, but instead form larger structures that outline potential territories. Moves like a two-space or three-space jump are usually referred to as extensions. The large knight’s move shown here is another extension usually only played near the edge of the board.

The diamond shape shown here is called a "ponnuki," the Japanese term for bloom, and is a very powerful shape. There is a Go proverb that says "A ponnuki is worth 30 points."

A ponnuki radiates power in all directions, and is very hard to attack. It creates one space on the board (right in the middle) that it is illegal for your opponent to play (unless capturing). It is progress toward creating a shape called an eye, which we will see is a very important concept.

A rough definition of an eye is that it is an empty space surrrounded by stones of one color (like a ponnuki) that can be connected into a chain of solidly connected stones surrounding the empty point. The following example shows that a group with one eye can be captured.

The rules of Go say nothing about eyes, but an important consequence of the rules is that a group with two eyes cannot be captured. A group with two eyes is said to be alive. A group that can be reduced to one eye (or no eyes) can be captured eventually and is said to be dead. The following example examines a group with two eyes.

It is worth saying again. This is a surprising consequence of the rules. The rules say nothing about eyes, but the need for a group to have two eyes emerges as perhaps the most important concept in Go! If you cannot give a group of stones two eyes, then that group of stones will be (eventually) captured. Making shapes with two-eyes is an extremely important skill!

Shapes are generally called "good" when they can easily be made into eyes, or when they form a solid connection. Here we outline some commonly occurring good shapes. If you make these shapes in your games, you are doing well!

Bad shapes are shapes that are very inefficient at creating eyes. Big clumps of stones with no eyes, sometimes called dumplings, are obviously bad. The following example shows a clump that might naturally arise in a game.

Another, perhaps more subtle, example of bad shape is what is called the "empty triangle." Strong players try to avoid making empty triangles if they can.

The final example more about tactics than specifically about shape. There is a Go proverb, "Don’t attach to a weak stone." The reason for this is that doing so generally makes the opponent’s weak stone stronger, and gives them an advantage over your attaching stone.

Now that we know about living and dead groups, and the importance of having two eyes, we can look at some common shapes and decide if they are alive or dead. A group that has two eyes is alive. A group that can be reduced to one (or fewer) eyes is dead.

If a three-space group is dead, what about a four-space group? The answer is that it depends! If the four spaces form a squareor a T-shape, Black can kill the groups. Any other arrangement of four spaces is generally alive. (There are some exceptions, but they are complicated and rare.)