Black escapes  

Here we see a generic side situation. For White to capture black immediately (that is, without giving it more than two liberties), she must place a stone that interferes with Black's escape.

Some killing moves

All of the marked white stones in the diagram above make it possible to capture black. There are many such combinations; these are just a few examples.

The sente moves  

The marked spots are sente against the Black stone : a White move at any of these spots threatens to capture Black immediately.

(A White move at some of these spots is sometimes called the Maeda method, after Maeda Ryo, who taught it in the US. But it is not clear exactly what he taught... the only sources so far are hearsay. There is a video by tuerda (4d North American amateur) which discusses this position and gives many applications.)

The marked spots are also effective depending on the ladder status.

Ladder ( connect)  

Outside influence

Black is often too low  

Even without supporting stones, White may try something like this for outside influence, which is often good for White ( may be at a or b, or at driving Black to the other direction). In such cases, Black may well abandon the stone.

Cutting stone

The sente moves  

When the stone is cutting, there are fewer effective supports. White may choose the "outside influence" sequence above.

Black sacrifice  

On the other hand, Black may play for outside influence himself by sacrificing the stone. This is often seen in practice. may be at a or b.

A related tesuji in joseki

Common Joseki  

This is a shape that occurs in a common joseki. White needs to protect the cutting point at a somehow.

White cooperates  

However, if white plays here, black takes an excellent shape point, creating a crocodile's mouth, and white cannot be satisfied. The same will occur if white protects the cutting point with either of the tiger's mouth plays (marked a). White should extend.

The joseki move  

is a joseki move; x and y instead of are also joseki. As you can see, after the exchange at a, at b, matches a marked spot in the "sente moves" diagram above.

See also Bishop's net for a related shape.

/old discussion