LeatherScrollProblem62/Attempts

How would b anwser?  

Reuven: Does it work?

Now miai to divide the big eye in the middle or to take a.  

Reuven: I don't think it's a miai, if W simply plays at a it's a ko now, isn't it?

ThorAvaTahr: Good move Reuven, though i see no ko for white.

White mistake part 3 Ko  

ThorAvaTahr: Thanks for the correction. However, I still think no ko, see below

Black dies without ko 2, continuation 1  

@

Black dies not without ko (likely to be the solution, white takes first)  

ThorAvaTahr: Thx again, i can't refute this. Therefore, I try a different first move, see below.

Black dies without ko 3  

Three lines in which black dies, I don't see other sensible lines. I think black two nobi results in unconditional death.

White mistake instead of above  

tapir: White needs three moves to connect its stones out. Black can live if he is ready to sacrifice the three stones. As this is a leather scroll problem this might be the solution. There are several endgame problem in this collection.

ThorAvaTahr: My mistake, should have been 1 immediately (corrected above)

Black dies without ko 5 part 1  

Black wants to live small using a but white doesn't take compromises.

Black dies without ko 5 part 2  

Black has ran out of liberties! -> no ko

How to make ko now? Part II  

If is played elsewhere at a captures some stones in the corner. There is no possibility for tricky under the stones tesuji in the corner as well (giving 4 stones in the corner for only one eye), as without capturing 4 in the corner threatens to take two more stones.

The trick is always the timing of the move at the 1-4 or 1-3 point threatening to make either two eyes or the ko. I am pretty confident that the solution is ko. (I did not read all variations though.) It seems this problem troubled me earlier XuanxuanQijingProblem158/Attempts

This is shapewise identical to the "double ko" in your variation. Imagine Black recaptures the central ko, and White takes the other one, now Black connects. The best White can do now, is fight the real ko. Taking a stone with is probably a more elegant way to the same end.

ThorAvaTahr: Correct, hmm I remember I found this result yesterday, but this morning I forgot again ;) However, you are sharp ;)

Does this mean the best result is ko, which white takes first (other branch)?

tapir: Thank you, I am flattered. It is the same result in this branch, a ko that white takes first. I would include both kos on a solution page (after clearing all other possibilities), because looking for a ko, that at first sight seems to be about only a false eye is somewhat unusual.