<p>Since T14 allows a sente hane, the initial board effectively looks like this:</p>

<pre><code>$$W
$$ ------------|
$$ . X O . . . |
$$ X . X O . . |
$$ . . X O . . |
$$ . . X O O . |
$$ . . X X O . |
$$ . . . O X 1 |
$$ . . . X 2 . |
$$ . . . . . . |
</code></pre>

<p>The usual attempt is to hane from the outside, then kill by playing at the vital point:</p>

<pre><code>$$ ------------|
$$ . X O 4 3 . |
$$ X . X O 7 2 |
$$ . . X O . 6 |
$$ . . X O O 5 |
$$ . . X X O 1 |
$$ . . . O X 8 |
$$ . . . X . . |
$$ . . . . . . |
</code></pre>

<p>But after 8, play cannot play at 1 to remove the eye due to atari.</p>

<p>Let's try a vital point in the corner directly:</p>

<pre><code>$$ ------------|
$$ . X O 6 . 8 |
$$ X . X O 4 1 |
$$ . . X O . 5 |
$$ . . X O O . |
$$ . . X X O 7 |
$$ . . . O X 2 |
$$ . . . X 3 . |
$$ . . . . . . |
</code></pre>

<p>After 8, the situation becomes a 2 step ko in b's favor.</p>

<p>Next, consider this sequence:</p>

<pre><code>$$ ------------|
$$ . X O . 4 5 |
$$ X . X O 1 2 |
$$ . . X O . 3 |
$$ . . X O O . |
$$ . . X X O . |
$$ . . . O X . |
$$ . . . X . . |
$$ . . . . . . |
</code></pre>

<p>After B5, the position is a direct ko. Black wins the ko by playing at 2, creating a dead shape inside. The same position arises if B1 is at B3.</p>

<p>However, thanks to the marked stone, black should try this:</p>

<pre><code>$$ ------------|
$$ . B O 6 5 . |
$$ X . X O 1 4 |
$$ . . X O 9 . |
$$ . . X O O 8 |
$$ . . X X O 7 |
$$ . . . O X 2 |
$$ . . . X 3 . |
$$ . . . . . . |
</code></pre>

<p>The shape is dead without ko.</p>

<p>In the original diagram, black can still aim for the same shape:</p>

<pre><code>$$ ------------|
$$ . X O O X . |
$$ X . X O 1 . |
$$ . . X O 5 . |
$$ . . X O O . |
$$ . . X X O 4 |
$$ . . . O X 2 |
$$ . . . X 3 . |
$$ . . . . . . |
</code></pre>

<p>After B5, white is short of liberties and dies.</p>

CC BY-SA 3.0
2013-02-05T17:21:12.473Z
2013-02-05T17:21:12.473Z
mafu
<p>Played a <a href="http://files.gokgs.com/games/2013/2/5/MrCactu5-onmyouji.sgf">game</a> on KGS.  We are both 4K.  He was good at life and death, and I am rusty.</p>

<p>Was B1 <a href="http://senseis.xmp.net/?Sente">sente</a>?  </p>

<pre><code>$$ ------------|
$$ . X O 2 1 . |
$$ X . X O . . |
$$ . . X O . . |
$$ . . X O O . |
$$ . . X X O . |
$$ . . . O X . |
$$ . . . X . . |
$$ . . . . . . |
</code></pre>

<go><tsumego>
Is this corner dead?
john mangual
# Is this corner dead?

(Asked by: username_0 on 2013-02-05)

Played a [game](http://files.gokgs.com/games/2013/2/5/MrCactu5-onmyouji.sgf) on KGS. We are both 4K. He was good at life and death, and I am rusty.

Was B1 [sente](http://senseis.xmp.net/?Sente)?

```
$$ ------------|
$$ . X O 2 1 . |
$$ X . X O . . |
$$ . . X O . . |
$$ . . X O O . |
$$ . . X X O . |
$$ . . . O X . |
$$ . . . X . . |
$$ . . . . . . |

```

**Tags:** go, tsumego


---

## 1 answers

### Answer by username_1 on 2013-02-05. Score: 6 | Accepted answer

Since T14 allows a sente hane, the initial board effectively looks like this:

```
$$W
$$ ------------|
$$ . X O . . . |
$$ X . X O . . |
$$ . . X O . . |
$$ . . X O O . |
$$ . . X X O . |
$$ . . . O X 1 |
$$ . . . X 2 . |
$$ . . . . . . |

```

The usual attempt is to hane from the outside, then kill by playing at the vital point:

```
$$ ------------|
$$ . X O 4 3 . |
$$ X . X O 7 2 |
$$ . . X O . 6 |
$$ . . X O O 5 |
$$ . . X X O 1 |
$$ . . . O X 8 |
$$ . . . X . . |
$$ . . . . . . |

```

But after 8, play cannot play at 1 to remove the eye due to atari.

Let's try a vital point in the corner directly:

```
$$ ------------|
$$ . X O 6 . 8 |
$$ X . X O 4 1 |
$$ . . X O . 5 |
$$ . . X O O . |
$$ . . X X O 7 |
$$ . . . O X 2 |
$$ . . . X 3 . |
$$ . . . . . . |

```

After 8, the situation becomes a 2 step ko in b's favor.

Next, consider this sequence:

```
$$ ------------|
$$ . X O . 4 5 |
$$ X . X O 1 2 |
$$ . . X O . 3 |
$$ . . X O O . |
$$ . . X X O . |
$$ . . . O X . |
$$ . . . X . . |
$$ . . . . . . |

```

After B5, the position is a direct ko. Black wins the ko by playing at 2, creating a dead shape inside. The same position arises if B1 is at B3.

However, thanks to the marked stone, black should try this:

```
$$ ------------|
$$ . B O 6 5 . |
$$ X . X O 1 4 |
$$ . . X O 9 . |
$$ . . X O O 8 |
$$ . . X X O 7 |
$$ . . . O X 2 |
$$ . . . X 3 . |
$$ . . . . . . |

```

The shape is dead without ko.

In the original diagram, black can still aim for the same shape:

```
$$ ------------|
$$ . X O O X . |
$$ X . X O 1 . |
$$ . . X O 5 . |
$$ . . X O O . |
$$ . . X X O 4 |
$$ . . . O X 2 |
$$ . . . X 3 . |
$$ . . . . . . |

```

After B5, white is short of liberties and dies.


---

