TsumegoFromGames81/Attempts

Table of diagrams ''a'' or ''b'' kills, ''c'' allows black to make ko. (c) W1 allows black to make ko. (b) Ko - White takes first (a) Another attempt (b) Plain (b) composition (A) (b) composition (A)i) (b) composition (A)i): direct capture often better style (b) composition (A)i): still safe (b) composition (A)i) (b) composition (A)ii) (c) composition (B) (a) 'a' above seems weakest only at first... (a) 'a' above seems weakest only at first... (a) W5 is wrong (a) W captures by damezumari-oshitsubushi (c) key move, var. 1 (c) key move, var. 2 (c) key move, var. 3 (c) key move, var. 4 (W6 @ B1)

a or b kills, c allows black to make ko.  

tderz Herman, where's the ko? (of your quote c allows black to make ko. )

(c) allows black to make ko.  

Herman Hiddema: Here it is.

tderz Bedankt, thanks!

(b) Ko - White takes first  

Tapir: At least this is the best I see for white. In the actual game black missed and played it at 4 instead. (KGS 5 kyu players both)

Dieter: there seem to be two ways to achieve a clean kill.

Tapir: Oh, i miss even two solutions? What a pity.

(a) Another attempt  

(b) Plain  

There seems to be nothing wrong with the plain - hane-connect. It's 3-2. Dieter

So white has three placements to achieve a clean kill (at each 1, 3 or 4 in the first diagram) ... Tderz seems to have one preference, but i don't see why that solution should be better than those (not the 1st mistaken one) given here. (Ko threats, endgame?) Tapir.

As far as i see both allow black to take some points in the corner and to make one outside play on the right side in sente.

(b) composition (A)  

tderz: I'm trying to compose here a position where the moves could make a difference.
After it is technically an approach ko ( at a; black ko threat c, at ; black ko threat d, at e, making it a direct ko at that stage.
Perhaps a better example can be constructed?

(b) composition (A)i)  

tderz: can Black get endgame m-n-o-p?
tderz: simply = r , Wp, Bo leads to ...

tderz: of corse, we could investigate = direct capture at r etc.

(b) composition (A)i): direct capture often better style  

tderz: ...often better style by White, but can she afford to give liberties to Black?

(b) composition (A)i): still safe  

tderz: ... yes, it would still be safe ..

(b) composition (A)i)  

(b) composition (A)ii)  

tderz: ... only when hallucinating, that's a ko.

(c) composition (B)  

tderz: in this case, is more active

(a) 'a' above seems weakest only at first...  

tderz: this is a standard ko ...

(a) 'a' above seems weakest only at first...  

tderz: 'a' above seems weakest as the ko is necessary once the white liberties are short, e.g 't' would be a Black stone ..., then = atari r, Bs would not work for White ...

(a) is wrong  

tderz: Black could link up, W would die ...

(a) W captures by damezumari-oshitsubushi  

tderz: W is saved ... (in the end it works for W)

tapir: Why is a weakest then? Black hasn't even taken the corner in this variation. And on the upper side for stones are in atari and the whole black group there is not particularly strong. A single stone on the upper side is more useful for black than a heavy group to care of in my humble (~4k) opinion.

tderz: You're right and I give you all the credits.
I've proven in lengthy explanations that a, b and c above seem very equivalent,
even, when purposefully trying to construct a difference ...

tapir: In the game, as written above, I played b with the intention to grant my opponent a ko and he played to convince me of black unconditional dead. However in all this discussion it puzzles me a lot, how many matters there are to look at in a "simple" situation like this. Especially, because i decided half a dozen moves earlier to tenuki on a black move here, which lead to this situation. Am I supposed to read this out that time? As well, while all 3 variants seems to allow white to capture and connect, I'm still not sure which one is best in terms of corner territory and black upper side potential. A complicated game.

tderz I haven't seen 2 of the 3 solutions either. Indeed complicated , that's why it is interesting !

tderz

(c) key move, var. 1  

(c) key move, var. 2  

(c) key move, var. 3  

or a

LukeNine45: One more that's worth mentioning:

(c) key move, var. 4 ( @ )  

/solution