Capturing Race Exercise 20 / Solution

Black first  

If Black plays first, then ensures life of his group as well as the death of the White group. Of course, this is not too interesting.

Death in gote  

Obviously, if White plays , then its 10 liberties to 6 liberties, so White dies in gote.

Solution  

The solution is for White to play at . If Black plays , then forms something like an eye in the belly, and Black is left with only 2 liberties.

Ko?  

It should be clear that has to be played inside his own eyespace. But how to answer ? If counting liberties is too much a hassle, then an easy way out is to create a ko with .

Solution  

In fact, wins the capturing race. Its 5 liberties to 6 liberties, so White is one liberty ahead.

Part II

Ko?  

With the stone, needless to say, if Black plays first, Black wins the capturing race. It seems that if White plays first, then and can set up a ko.

Solution  

However, prevents White to create any ko. So the status of the White group is actually dead, with Black having 6 liberties and White having 5 liberties.

Actually, if the reader have noticed for Part I, then there is nothing to solve for Part II. This also implies that in Part I, if Black plays first, then playing at is more likely a better move than making life, since has more influence on the outside.