Beginner Exercise 122 / Solution

Solution  

is a blunder, as the wedge at captures the Black stones. Due to shortage of liberties, Black a would be self-atari.

Continuation  

If Black resists with , then forces the win.

Snapback  

If , then catches Black in a snapback.

Descent  

Black's descent with still cannot save him.

How black should have played  

at a was a blunder. Black should have played here instead. Now is captured.

If white tries to escape...  

If here, then all the white stones are captured. (This is an example of where One-Two-Three doesn't work!) For how white can save part of the group, see the variations at Kyu Exercise 75.