11thNongshimCup/Stage 1 Game 2

Sub-page of 11thNongshimCup

White: Kim Jiseok (6d)

Black: Ding Wei (9d)

Result: W+Resign

Location: Beijing, China

Date: November 26, 2009

[ext] SGF

Table of contents Table of diagrams
Moves 1 to 10
Moves 11 to 20
Moves 21 to 30
Alternate continuation
Moves 31 to 40
Moves 41 to 50
Moves 51 to 60
Moves 61 to 70
Moves 71 to 80
Moves 81 to 90
Moves 91 to 100
Moves 101 to 110
Moves 111 to 120
Moves 121 to 130
Moves 131 to 140
Moves 141 to 150
Moves 151 to 160
Moves 161 to 170
Moves 171 to 180
Moves 181 to 190
Moves 191 to 200
Moves 201 to 210 (8 at 2)
Moves 211 to 220
Moves 221 to 230
Moves 231 to 240 (9 at 3)
Capturing race continuation
Capturing race continuation
Position at 324?
Index of sub-pages

[Diagram]
Moves 1 to 10  

emeraldemon(5k): I almost always play this joseki to completion, but I notice pros seem to very often choose the tenuki variation. Maybe one of the dangers of learning joseki is that we always want to finish them.

[Diagram]
Moves 11 to 20  

I think if this joseki were on SL it would be at 4-4 point low approach, two-space high pincer, without side stone, but I don't see it there. --emeraldemon

tapir: Look at 4-4 point low approach, tsukenobi, jump attachment. It is played similarly after a double approach (the stone at W2 has quite a lot of aji and often can make life by threatening to connect with the corner, B1 here allows black to push more than once, which would be bad otherwise)

[Diagram]
Moves 21 to 30  

emeraldemon: I was thinking about what happens here if B9 is at W10:

[Diagram]
Alternate continuation  

Black is gote here, unlike in the game, but has considerable thickness towards the left, keeping the corner group sealed in. On the other hand, white has a potential move around a, and the capture of that stone seems much smaller now. Any thoughts?

Tapir: Less black influence on the top and a beautiful placed white+circle to deny the Black wall an extension. Black may omit B5 but then it becomes a nice place for white to play (making territory next to Black's wall.

[Diagram]
Moves 31 to 40  
  • tapir (kgs 1d): the standard probe at W40 occurred similar in the first game under the high shimari. i feel at my level, the use of probes is something not well understood.
  • emeraldemon: If they're not understood at your level, how much less so at mine! If I had been in this position in a game, black's influence on the right side would probably make me try a speculative invasion somewhere around a. But white calmly plays W8, then the probe at W10, and uses the aji from the W10 stone to develop a decent living group on top. Those sorts of attack/reduction sequences I find especially hard to manage, and I think partly because you have to be very flexible in responding to the opponent. Certainly by move 60 in this game black is even stronger on the right side, but white still wins in the end.
  • tapir: Is it still strong, or even overconcentrated :)
[Diagram]
Moves 41 to 50  
[Diagram]
Moves 51 to 60  
[Diagram]
Moves 61 to 70  
[Diagram]
Moves 71 to 80  
  • tapir: I see, that answering B73 by connecting would be slow and would allow black strengthen his group while attacking... but W74 is incomprehensible to me. (Though W74 reduces B73 liberties so that it can not push and cut instantly. Because white has a ladder to capture then.) More reasoning about this move recommended.
[Diagram]
Moves 81 to 90  
[Diagram]
Moves 91 to 100  
[Diagram]
Moves 101 to 110  
[Diagram]
Moves 111 to 120  
[Diagram]
Moves 121 to 130  
[Diagram]
Moves 131 to 140  
[Diagram]
Moves 141 to 150  
[Diagram]
Moves 151 to 160  

unkx80: Once White connects the ko, Black has definitely lost the game because Black will have to play moves inside his territory to capture the White stones. I suspect Black might have lost the game earlier around move 110, but I am not so sure about this.

[Diagram]
Moves 161 to 170  
[Diagram]
Moves 171 to 180  
[Diagram]
Moves 181 to 190  
[Diagram]
Moves 191 to 200  
[Diagram]
Moves 201 to 210 (8 at 2)  
[Diagram]
Moves 211 to 220  
[Diagram]
Moves 221 to 230  
[Diagram]
Moves 231 to 240 (9 at 3)  

This final ko is very puzzling and difficult for me to understand. First, just to be clear, white truly has won this ko:

[Diagram]
Capturing race continuation  
[Diagram]
Capturing race continuation  

Now white can capture at a, and no threat could possibly prevent the capture. Because the ko is much bigger than any of the threats on the board, white wins it by virtue of taking first. Given the huge size of the ko, why does black respond to W234?

[Diagram]
Position at 324?  

The threat at a can't possibly be worth more than 8 points, compared to the easily 30 point ko. Why doesn't black ignore the threat and play at b? As best I can tell, Black wants to play like a komaster and not have to ignore any threats, because even winning the ko black will lose if he loses those stones. Is this close?

  • tapir: Let us count. Only life and death of the two groups the black one and the white one (+ surrounding points) is about 70 points. But white wins the ko in sente, because black has to make life in the corner.

11thNongshimCup/Stage 1 Game 2 last edited by 50.23.115.116 on January 26, 2015 - 08:08
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