Beginner Exercise 47 / Solution

Solution  

creates a ko. Black cannot respond at a because of shortage of liberties. Any response that does not threaten (except b, discussed below) will capture the two black stones at the right in a snapback (White b, Black a, White b).

Solution  

connects and sets up the ko in which Black takes first at a. If White wins the ko, he captures four Black stones at b.

If Black wins the ko  

If Black wins the ko, Black lives with and .

White can't avoid ko  

Black cannot avoid the ko by connecting at , as captures all the Black stones.

Inferior for Black  

Black can also start a ko with . However, this ko is inferior for Black when compared to the solution because after takes the ko, Black has to find the first ko threat (see try to get first capture in a ko).