4435 enclosure

    Keywords: Opening, MiddleGame, Joseki

Table of contents


4435 enclosure  

The assumption is that this is made from the initial 4-4 point.

Reduction moves

reduction 1  

This is a standard way to reduce a framework based on 4435. The 3/4 exchange may sometimes be omitted.

From the 3453  

Starting from the 3453 enclosure, B2 after W1, rather than Black a, is possibly too steady (though one can hardly call it a mistake - it's one possible answer to this as middlegame joseki). This accounts for White's willingness to force Black in the reduction sequence.

reduction 2  

Calvin: Another idea which is common in pro play is for white to invade at the 3-3 and then attach at W3. W3 makes miai of a and b. If black plays a, white can make a position on the left side. If black plays b, attempting to seal white in, it is not clear white can live but the aji will be bad (see below).

3-3 invasion

The 3-3 invasion in this position cannot live, but may be useful in other ways. Sometimes it can function as a probe.

See also : 3-3 point invasion query 6


Early endgame sequence  

Exchanging W1 for B2 gives White a big endgame play at 3. Black needs another move at a to secure the corner, so this should be played in the early endgame, when it ought to be sente.


If Black reacts on the other side to the marked play, White gains life in the corner.

Attemps to live

3-3 Invasion  

The case in which White has stone at circle is important, because black+circle is often played in response to this approach. But even so, the invasion cannot live (Timm: strong player please check this).

Hane under  

Black should normally answer white+circle at B2. Then White can try the hane at W3.

Hane under : no ko  

White cannot live locally, but there is bad aji at a.

Diagonal move  

White can also try the diagonal move at W3.

Diagonal move, countermeasure 1  

After B10, there is no escape

tapir: A white stone at CC threatens to connect out.

Diagonal move, countermeasure 2  

After B10, a and b are miai for black. Note, however, that if white can play the hane at c in sente then white can live after that with b.

White can also choose to play W7 outward at B8, allowing black to cut. That way, white will lose the corner, but may live along the top side.

3-3 Invasion  

B4 is bad. White is alive after W5, .

Three crows enclosure


This formation may arise from the 4435 enclosure, usually with at least one white stone at a or b. It is known as the Three Crows.

3-3 invasion  

Even with both white+circle stones in place, the invasion at W1 need not succeed. B4 is something of a concession (see two diagrams above for the reason, in a related case), but the corner is then safe enough.


With just white+circle in place, Black can try B2 (or Black at a) in reply to W1. The feeling is then to avoid being forced, and make W1 into mochikomi.

That is at the cost of some bad aji here for Black. In pro games W1 can be played as a probe.

Charles Matthews

4435 enclosure last edited by Timm on March 29, 2015 - 00:40
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