Beginner Exercise 85 / Solution

The toughest try by Black  

is the only move to live. must be answered by - and certainly not or . One suffers from shortage of liberties, and the other lets Black kill at .

Variation  

If here, is the only play that secures life.

Failure 1  

looks like making two eyes, but due to the descent at , Black can play . Now White can only live by a ko at .

(Note that at a is wrong - see below.)

Failure 2  

If here, then hits the critical spot, and White is dead.

continued: Double ko death  

If White throws in with , takes one of the kos. Now if White plays at a or b, Black fills with , holding White to one eye.

Double ko death (ii)  

(After and elsewhere)

If White later takes the ko back with , takes the other ko. Now if White connects at , Black connects at and kills.

Failure 3  

fails to .