4-4, double low approach, attach-extend, 3-3 invasion

Keywords: Joseki

The 3-3 invasion of is a variation of the 4-4 point, double low approach, attach-extend joseki. The typical Black responses are a and b. Black c is rarely a good choice.

When enters the 3-3 point, and is a common joseki for controlling the upper side.

If Black has support at black+circle or a, then will be played here instead of b to avoid overconcentration.

may also choose to connect, in which and are sort of a tesuji. After , if White a then Black b, and if White b then Black a, so Black may have an opportunity to attack the White stones at the top.

If is played at , then Black c takes the corner.

at the 2-2 point is also a common tesuji. Subsequently, and B10 are miai.

The hane at here is rare in professional games, because and connects the corner to the top side, acquiring a sizable amount of territory and possible expansion along the top side. In compensation, Black gets a wall on the left side, but it appears inferior to White's territory.

This sequence is seen in a game between Huang Dexun (White) and Jiang Zhujiu (Black), colours reversed. The game took place in China, 1981, with Black winning by resignation.

The block on the left side is usually played when there the left approach stone is also being pincered by black+circle or Black a.

can also choose to connect, then cuts and puts pressure on the three-stone White chain.

Blocking the 3-3 stone this way is rarely good. While White is settled on the left side, did not put any pressure on the white+circle stones. Now, the stones are light and can easily be sacrificed.