11thNongshimCup/Stage 1 Game 2

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.

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 has quite a lot of aji and often can make life by threatening to connect with the corner, here allows black to push more than once, which would be bad otherwise)

Moves 21 to 30  

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

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 to deny the Black wall an extension. Black may omit but then it becomes a nice place for white to play (making territory next to Black's wall.

Moves 31 to 40  

• tapir (kgs 1d): the standard probe at 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 , then the probe at , and uses the aji from the 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 :)

• tapir: From Fujisawa Hideyuki Dictionary of Basic Tesuji: "They say you are at least 5 dan if you correctly seize opportunities to make this 3-3 point attachment." So don't worry too much :)

Moves 71 to 80  

• tapir: I see, that answering by connecting would be slow and would allow black strengthen his group while attacking... but is incomprehensible to me. (Though reduces liberties so that it can not push and cut instantly. Because white has a ladder to capture then.) More reasoning about this move recommended.

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.

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:

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?

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.