# Worst Move Problem 11 / Solution

unkx80: This looks like a problem in the Gokyo Shumyo or the Igo Hatsuyo-ron series, but I can't recall which.

char: Heh, you caught me; I got the idea of this problem from those classical problems. I will post the rest of the comments below Herman Hiddema's solution.

## Solution

Herman Hiddema: After , black can live by playing *a*. However, the question was for white to make black alive, not to make the situation unsettled. So suppose we allow white to play at *a*, the question then is:

## Char's Comments:

First of all, the problem might as well be like this.

On the second thought, since the "worst move" problems has a pretty high attempting/solving rate compare to other problems on SL, I decided to sneak more information in the problem ^^

I guess the ko you are thinking about is like this.

If at , black can resist with

In this one, white solves the ko problem by letting black capture one more stone.

In the original problem, because of , Herman Hiddema's sequence works. Also, the clamp at works here.