4-4 point 3-3 invasion double hane

  Difficulty: Advanced   Keywords: Joseki

Table of contents

Initial position

Two step hane  

This variation stems from the 4-4 point 3-3 invasion page. Instead of extending at a as in the usual sequence, Black can play the double hane at B3. Black will do this if he is prepared to take the corner at some extra cost or, if White resists, fences in White in the corner, or to keep the initiative.

Although this is called joseki, and is a common technique, some variations are difficult, and are affected by stones near the circle-marked point.

Variation 1: taking the corner

Taking the corner  

A straightforward variation is when W1 cuts and captures what has become a cutting stone. Black can then sacrifice the cutting stone and capture the corner. The two step hane has played the role of cut the side you don't want.

Evaluation of the position  

This variation has proved very popular with AIs such as LeelaZero and Minigo during a certain phase of their training; the AI community took to calling it the flower joseki, alluding to the resulting ponnuki, as noted in [ext] this forum topic.

Subsequent moves  

Subsequently, W1 may become a big point, igniting a pushing battle by threatening the hane at a. For this reason, W1 at W3 would be slack. Typically Black responds at B2 if he chooses not to ignore W1, and up to B6 is a common sequence. Note that if Black plays B4 at W5, then Black loses the corner: see the next diagram.

Double hane  

Black would probably like to play the double hane of B1 in this diagram, but here the aji of the marked white stones come into play. White can retake the corner -- or worse.

Two step hane  

This side stepping by Black does not really produce a good result, leaving weaknesses at a and b in gote. This is especially as Black usually chooses this joseki (two step hane after the 3-3 invasion) when a wall facing the top side is not very valuable, opting instead to take points in the corner.

Corner aji (1)  

If White gets the marked stone in place, W1 will either link up as in the diagram or capture the marked black stones.

Corner aji (2)  

The other aji is that W1 and W3 threaten to extract the marked stones in the same way as above, so that W1 becomes almost absolute sente. This in itself is not so bad, but it could be a minus if Black's reason for not following the standard sequence was that the top side is not interesting. According to GoBase, Black's responses to W3 include a, b and c. If Black has a suitable extension on the right side, Black can also respond at d.

Black move  

If White chooses to tenuki, Black may choose to exchange B1 with W2. Subsequently, Black may hane at a, but in professional games Black is also seen to tenuki after the exchange (simply to prevent White from getting W1).

Building influence  

If Black wants to build up the upper side, he can play B1 immediately.

Black attack  

If Black has support on the left side, say black+circle, then Black may elect to attack at B1. In professional games, W2 is seen replying at either a or b.

Note that without the support of stones such as black+circle, a Black move at B1 is very likely to end up being a misplaced stone.

Variation 2: influence and/or initiative

Influence and/or initiative  

W7 @ black+circle. White must not play W5 at B6 or Black will take the corner as in the above, while increasing his influence. In this variation, Black can now take the initiative to play elsewhere, extend his wall around a or increase his influence towards centre and sides at b.

Variation 3: White's counter hane

White's counter hane  

If Black plays the double hane, Black has to be prepared for this W1. White intends to give up the corner in exchange for a position on the top. In an emergency, however, instead of B2 Black may play at a; the likely outcome is that he gives up a bit more territory in the corner in order to maintain his outside wall.

W1 is now almost always regarded as a mistake by AI. Previously, it was regarded as a situational joseki, useful in cases where black has staked everything on making a big moyo at the top so that W1 does more damage to the moyo than it loses in the corner. But recent analysis seems to indicate that the damage is hardly ever worth giving away a larger corner (see [ext] https://lifein19x19.com/viewtopic.php?f=15&t=17352).

Incidentally, this variation has been coined "switcheroo ponnuki" by Uberdude.


After W3 in the previous diagram, B1 is the joseki move, reaffirming the unity of the black stones. After B5, White can secure a base with a move like a or play tenuki.

Black resistance  

With black+circle in place, Black can resist. White can live - very small in the corner or belatedly take the other ponnuki starting at a. However this is worse than taking the other ponnuki directly.

The presence of extra stones


After the variation "taking the corner" White will most likely continue with these moves. In most cases, when White invades at the 3-3 point, Black has stones on both sides, at or around the places shown here. Black's left side stone has lost much of its value after this sequence.

Slightly vulgar?  

In White's counter hane variation, this atari play is recognised as joseki, but is highly sensitive to stones on the upper side, for example at a or b in the following diagram.

To take the outside  

These plays occur in pro games. When Black plays B3, White will eventually have to live at e. Before that White has a chance of pulling out the marked stone with White c, Black d and White continuing on the third line for a while. The books teach that this is good for White if Black has a stone at b, but poor if Black has a stone at a.

If White lives immediately at e and Black tidies up by capturing at c, Black will be thick anyway (possibly slightly overconcentrated).

There's an early example in Chapter 1 of Beauty and the Beast.

[4] Double Hane: As with so many novelties, it has been seen much earlier. In the case of this joseki, Kajiwara Takeo played it as early as 1958.

4-4 point 3-3 invasion double hane last edited by yuzukitea on September 10, 2021 - 22:56
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