Beginner Exercise 171 / Solution

White connects  

the proper move. Black only really has two choices to resist white's connection.

Black tries to resist  

There's this rather poor choice which easily allows White to push through with , and not only connect, but also capture 3 black stones.

White connects  

is a bit trickier. is a double atari. captures , but then captures to connect.

White connects over the other stone  

togo: (Nearly) same thing with Black playing on the other side. Then again is a double atari. captures , but then captures to connect.

Irrelevant variation  

togo: captures and connects, too, but in a less solid way (presenting Black with a ko-threat). Nonetheless it's interesting shapewise: If you imagine a white stone at 'a', then not only captures , but creates a backsnapping eye at (which would be ko-dependent with on 'b' as before).

Failure  

White almost gets a ladder going.