<p>In the deviated form, white can play at <code>B18</code> and the corner will live or die as a ko, or it can end up in seki.  Even if black has more than enough ko threats to win the battle, it is unlikely ever worth it.</p>

<pre><code>$$Wcm4 Continuation of deviation: Ko
$$ +---------------------------------------+
$$ | 7 . 3 6 5 . . . . . . . . . . . . . . |
$$ | 2 1 a X X O . . . . . . . . . . . . . |
$$ | . X X X O O . . . . . . . . . . . . . |
$$ | 4 X O O . . . . . , . . . . . , . . . |
$$ | O O O . O . . . . . . . . . . . . . . |
$$ | . X X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
</code></pre>

<p>The corner lives or dies depending on who wins the two stage ko; black's normal defense of playing <code>7</code> at <code>a</code> won't work due to a shortage of liberties.</p>

<p>Alternatively, if white does not have sufficient ko threats the whole corner could end up as a seki as follows:</p>

<pre><code>$$Wcm4 Continuation of deviation: Seki
$$ +---------------------------------------+
$$ | 8 a 3 6 5 7 . . . . . . . . . . . . . |
$$ | 2 1 . X X O . . . . . . . . . . . . . |
$$ | . X X X O O . . . . . . . . . . . . . |
$$ | 4 X O O . . . . . , . . . . . , . . . |
$$ | O O O . O . . . . . . . . . . . . . . |
$$ | . X X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
</code></pre>

<p>Note that in this variation, black can choose to start the same ko by playing <code>11</code> at <code>a</code> instead.</p>

CC BY-SA 3.0
2012-01-23T22:41:19.417Z
In the first example, black 5 looks like a mistake.  What happens if black responds at White 8?  I see White C19, Black A16, White A18, Black B19, White A19, Black C18 for seki.  White can still force a ko by playing A18 at A19, but now it's an approach ko for white.  And no longer two step.
OmnipotentEntity
CC BY-SA 3.0
2012-01-23T23:37:06.253Z
@OmnipotentEntity: White avoids the approach ko with A16 instead of C19.  I believe the best black can hope for there is a direct ko with white capturing first.
goldPseudo
CC BY-SA 3.0
2012-01-24T02:04:51.527Z
Well, you have my vote. :)
OmnipotentEntity
CC BY-SA 3.0
2012-01-22T21:30:43.823Z
2012-01-22T21:55:02.507Z
2012-01-22T21:55:02.507Z
goldPseudo
<p>I know the following is joseki for an approach of the 4-4 stone followed by a 3/3 invasion...</p>

<pre><code>$$cm1 A normal 3/3 invasion joseki (incomplete)
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 7 3 . . 2 . . . . . . . . . . . . . |
$$ | . 5 4 O . . . . . , . . . . . , . . . |
$$ | . 6 8 . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
</code></pre>

<p>.. and this is a possible continuation:</p>

<pre><code>$$cm1 Continuation of the joseki
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 7 . . . . . . . . . . . . . . . |
$$ | . X X 1 2 O . . . . . . . . . . . . . |
$$ | . X O O . . . . . , . . . . . , . . . |
$$ | 4 O O . 6 . . . . . . . . . . . . . . |
$$ | . 3 X 5 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
</code></pre>

<p>If I understand correctly, a white move at E18 has to be answered by black, or white A16 kills. <a href="http://eidogo.com/#kjd%3apdqfncqcqdrdrercqepcocrfsepfoe">Eidogo</a> lists only black 7 as above at this point. It does not list the following variation, hence, I assume it is somehow bad for black, but I am not sure why.</p>

<pre><code>$$cm1 Deviation from joseki
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 3 1 2 . . . . . . . . . . . . . |
$$ | . X X X O O . . . . . . . . . . . . . |
$$ | . X O O . . . . . , . . . . . , . . . |
$$ | O O O . O . . . . . . . . . . . . . . |
$$ | . X X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
</code></pre>

<ul>
<li>Am I correct that black is alive like that? If not, please show how to kill black.</li>
<li>Given that black is alive in both variants, why would one prefer the default variant? I first thought that 7 may be sente, but with E18 threatening to kill it seems gote just as well, while getting fewer points?</li>
</ul>

<p>(I'm sorry if this is a duplicate question, but I have no idea how to search a stackexchange site for go-deviations really)</p>

CC BY-SA 3.0
2012-01-23T02:26:23.280Z
I believe playing 3 at D19 in the deviation would let the corner live unconditionally.
goldPseudo
CC BY-SA 3.0
2012-01-23T12:03:46.910Z
We do not yet have a good way to search for specific positions or joseki sadly ;( Btw, I see this is your first question here (and already really well formatted!), so welcome on Board and Card Games :)
mafu
<go><joseki><joseki-deviation>
Deviation of 3-3 invasion - how to live/kill?
Frank
# Deviation of 3-3 invasion - how to live/kill?

(Asked by: username_0 on 2012-01-22)

I know the following is joseki for an approach of the 4-4 stone followed by a 3/3 invasion...

```
$$cm1 A normal 3/3 invasion joseki (incomplete)
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 7 3 . . 2 . . . . . . . . . . . . . |
$$ | . 5 4 O . . . . . , . . . . . , . . . |
$$ | . 6 8 . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |

```

.. and this is a possible continuation:

```
$$cm1 Continuation of the joseki
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 7 . . . . . . . . . . . . . . . |
$$ | . X X 1 2 O . . . . . . . . . . . . . |
$$ | . X O O . . . . . , . . . . . , . . . |
$$ | 4 O O . 6 . . . . . . . . . . . . . . |
$$ | . 3 X 5 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |

```

If I understand correctly, a white move at E18 has to be answered by black, or white A16 kills. [Eidogo](http://eidogo.com/#kjd%3apdqfncqcqdrdrercqepcocrfsepfoe) lists only black 7 as above at this point. It does not list the following variation, hence, I assume it is somehow bad for black, but I am not sure why.

```
$$cm1 Deviation from joseki
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 3 1 2 . . . . . . . . . . . . . |
$$ | . X X X O O . . . . . . . . . . . . . |
$$ | . X O O . . . . . , . . . . . , . . . |
$$ | O O O . O . . . . . . . . . . . . . . |
$$ | . X X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |

```

* Am I correct that black is alive like that? If not, please show how to kill black.
* Given that black is alive in both variants, why would one prefer the default variant? I first thought that 7 may be sente, but with E18 threatening to kill it seems gote just as well, while getting fewer points?

(I'm sorry if this is a duplicate question, but I have no idea how to search a stackexchange site for go-deviations really)

**Tags:** go, joseki, joseki-deviation

> **Comments:**
> **username_1**: I believe playing 3 at D19 in the deviation would let the corner live unconditionally.  
> **username_2**: We do not yet have a good way to search for specific positions or joseki sadly ;( Btw, I see this is your first question here (and already really well formatted!), so welcome on Board and Card Games :)  

---

## 1 answers

### Answer by username_1 on 2012-01-22. Score: 9 | Accepted answer

In the deviated form, white can play at `B18` and the corner will live or die as a ko, or it can end up in seki. Even if black has more than enough ko threats to win the battle, it is unlikely ever worth it.

```
$$Wcm4 Continuation of deviation: Ko
$$ +---------------------------------------+
$$ | 7 . 3 6 5 . . . . . . . . . . . . . . |
$$ | 2 1 a X X O . . . . . . . . . . . . . |
$$ | . X X X O O . . . . . . . . . . . . . |
$$ | 4 X O O . . . . . , . . . . . , . . . |
$$ | O O O . O . . . . . . . . . . . . . . |
$$ | . X X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |

```

The corner lives or dies depending on who wins the two stage ko; black's normal defense of playing `7` at `a` won't work due to a shortage of liberties.

Alternatively, if white does not have sufficient ko threats the whole corner could end up as a seki as follows:

```
$$Wcm4 Continuation of deviation: Seki
$$ +---------------------------------------+
$$ | 8 a 3 6 5 7 . . . . . . . . . . . . . |
$$ | 2 1 . X X O . . . . . . . . . . . . . |
$$ | . X X X O O . . . . . . . . . . . . . |
$$ | 4 X O O . . . . . , . . . . . , . . . |
$$ | O O O . O . . . . . . . . . . . . . . |
$$ | . X X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |

```

Note that in this variation, black can choose to start the same ko by playing `11` at `a` instead.

> **Comments:**
> **username_3**: In the first example, black 5 looks like a mistake.  What happens if black responds at White 8?  I see White C19, Black A16, White A18, Black B19, White A19, Black C18 for seki.  White can still force a ko by playing A18 at A19, but now it's an approach ko for white.  And no longer two step.  
> **username_1**: @username_3: White avoids the approach ko with A16 instead of C19.  I believe the best black can hope for there is a direct ko with white capturing first.  
> **username_3**: Well, you have my vote. :)  

---

