4463 enclosure 2-5 approach

Very low approach to 4463  

One way to enter a framework built up around a 4463 enclosure is with on the second line, sometimes called a submarine. This gives better chances of unconditional life than the 3-3 invasion, which normally becomes ko. On the other hand: there are some complex variations possible; White may need to apply sabaki techniques; and it is undeniable that White may end up with a low position.

White will often invade this way when black has a stone at or near . One key idea here is that the directions of a and b are miai.

Black's answers  

In pro games, four replies from Black are most commonly seen. In order of popularity, they are:

• a: 4463 enclosure second-line side attachment
• b: 4463 enclosure second-line diagonal attachment
• c and d are discussed below.

Naturally, since this is a middlegame joseki, any nearby stones may have a big effect on the choice of direction and subsequent fighting.

variation c  

When black plays , white's most common answer is at or near . The following moves depend on the surrounding positions. Sometimes white will play b immediately to make eye shape; more often white will wait until later to decide between a and b. Black will usually play at or near d to chase white into the centre, but sometimes black will press at c.

variation d  

is only usual if there is no stone around a. The reason is that White can live comfortably in the corner. If there is a black stone around a that is too much to give her, but with no stone there, denying her the corner will give her a comfortable position on the side, so it is not as much of a disadvantage. Still, even in that case, if Black wants to confine white to the corner, Black b instead of is more usual.

standard sequence  

Although would be enough to live, White will crawl at once to avoid being completely hemmed in on this side. After , White can make a living group with either or White a. is obviously better endgame at the top, but White a leaves some aji of cutting. If Black does not want White to play a, he exchanges Black a for White b before playing ; however, if White would have played anyway, this exchange becomes aji keshi.