Small board Go / Three By Four Solution

Sacrifice for ko  

Black throws in with and , then connects with .

Ko  

White has no defense.

Correct play (Japanese)  

Therefore, the original position is bad for White. Instead, descends. is a throw-in for shortage of liberties.

Seki  

Black gets 2 points for the two prisoners.

Correct play (Chinese)  

Black wins by 4.

Note that by stone counting, Black wins by 3 points either way. In the second diagram Black needs one (false) eye for life.