This is the most direct solution. and
reduces black's liberties and forces
and
to capture the four white stones.
Although black wins the capturing race, the resultant eye shape is a farmer's hat, which is killed by .
is yet another solution. After
, if black plays at a, black puts himself into self-atari. (It is also possible to reverse the order of
and
to kill, but
will be postponed in practice).
After ,
directly occupies the vital point. Even when
desperately tries to create the second eye,
is an atari on four black stones including
. Now if black connects at a, then he dies in gote.
Comparison: The marked stone may have some good effect to the right. On the other hand, this line gives Black an additional ko threat.
However, directly kills.
and
are now miai. In the end, whether
is a white stone or a black stone, we still have at least two solutions.