# Gokyo Shumyo, Section 1, Problem 40 / Solution

Black to live

is the vital point. It clearly makes one eye at the circled point, and White can't prevent another eye to the left of .

Main line
Continuation 1

Note what a difference an extra white stone at a would make.

Continuation 2

Again, an extra stone at a would make the difference.

Once the vital point has been played - in the main line - the rest is not so difficult any more. Finding that point is the main challenge here. Let's have a look at how things can go wrong.

Failure 1a

One is tempted to cover the two-space gap with a move like here. However, White strikes at the vital point. If at , then at .

Failure 1b

This results in ko.

Alternate play 1a

ChrisR: White can avoid the ko by playing first, then . Black's group is dead.

Yohei: Black is not dead - he can make seki as shown below.

Alternate play 1b
Failure 2a

ChrisR: Playing at is a failing move, but it is better than playing at 3. Up to , this is seki.

Yohei: White won't be so kind. in the following diagram kills.

Failure 2b
Failure 2c

Taking the vital point now is too late. kills.

Failure 2d

Maximising his eye space does not work.

Failure 2e

here does not work either.

Go to Problem 41

Gokyo Shumyo, Section 1, Problem 40 / Solution last edited by 138.251.241.132 on July 10, 2009 - 04:43