BlindSpot/Problem 4 Solution

Solution  

Chaz: Plays at a, b, c, and possibly d are the obvious places to play, but is the only solution that kills unconditionally. After , a and c are miai for the kill, along with b and d.

Ko ( at )  

here is probably the best failure. If not for Black's two liberties he would not be able to create double atari with .

Ko (captured removed)  

White now has to win a ko, which is suboptimal given she can kill unconditionally.

Ko again ( at )  

here achieves the same result.

Variant 3 at 4  

What about 3 at 4? Isn't B left with just one eye? -C13

Variant 2 at 4, type 1  

And if 2 at 4, then we get a ko favourable for W, no? -C13

Failure  

After , a and b are miai for life.