2

In Nick Sibicky's lecture #246, they state that the black group at T3 is dead:

enter image description here

They exactly say that both have 4 liberties and it's White's move so Black is dead.

But, after Black connects at S3 and white takes outside liberty at S5, Black can gain one extra liberty: T5 (threatening to run out), White S7, T6, S8 and Black now has 4 liberties and is on the move! Plays O1 and wins the race.

Like this:

$$Bcm1 
$$ |...,.....,
$$ |..........
$$ |..........
$$ |.XXX......
$$ |7OOOX.....
$$ |.OXXOO....
$$ |.OXO.....,
$$ |.OXOO.....
$$ |.X1X2.46..
$$ |.XXX35....
$$ +----------

Or rotated to agree with their coordinates:

$$Bcm1 
$$ ..........|
$$ ..........|
$$ ..........|
$$ ,.....,...|
$$ ..........|
$$ ........6.|
$$ ........4.|
$$ .....O...5|
$$ ....XO.O23|
$$ ,..XOXOOXX|
$$ ...XOXXX1X|
$$ ...XOOOOXX|
$$ ....7.....|
$$ ----------+

Or did I miss something?

5

Instead of S8, White can play T7. This may not work right away because White has some bad shape, but if he lets black crawl a few times - T5, S6, T6, S7, etc - and then blocks on the edge, the group doesn't gain any liberties.

Like this:

$$Bcm1 
$$ |...,.....,
$$ |..........
$$ |..........
$$ |.XXX......
$$ |7OOOX.....
$$ |9OXXOO....
$$ |.OXO.....,
$$ |.OXOO.....
$$ |0X1X284...
$$ |.XXX356...
$$ +----------

Or this:

$$Bcm1 
$$ |...,.....,
$$ |..........
$$ |..........
$$ |.XXX......
$$ |.OOOX.....
$$ |.OXXOO....
$$ |.OXO.....,
$$ |.OXOO.....
$$ |.X1X246.8.
$$ |.XXX35790.
$$ +----------
  • It doesn't block on the edge... because black has stone at S14, so he would connect to it. – Tomas Nov 8 at 21:27
  • 2
    T7 works fine. If black push with S6 white just blocks. Black can attempt to cut at R7, but the black group is down to 2 liberties, so white will just atari. – Taemyr Nov 8 at 22:29
  • 2
    @Tomas TimK is pointing out that if white is worried about the shape issues on his R4 group he could let black crawl along the edge for a while before aiming to block. White will not let black crawl all the way to the S14 stone. After white jumps, if black continues to crawl white will descend to the edge and black will have nowhere to go. It's a distraction though because white can just play the jump immidiately with S7 and answer T6 with T7, black has too few liberties to accomplish anything. – Taemyr Nov 8 at 22:34
  • thanks Taemyr for additional explanation! :-) With this, the answer works! :-) – Tomas Nov 9 at 14:57

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