4463 enclosure 2-5 approach
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.
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.
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.
Black will normally answer this way when there is no stone near a. White can live in the corner by playing b, but will usually crawl once at c first, as shown in the next diagram.
Authors:
July 2007: WME and some new material by xela, but it would be good to have this page reviewed by someone who actually understands it :-)