is the only correct move. If
tries to destroy the eye at the top, White can block at
. With the marked stone, Black cannot play at a to connect
. So
is effectively captured, and White lives.
Jacob4Jesus: Doesn't at
kill? Is there a better play than
?
JoelR: No, If at
, then
at
. Please read these things out, making note of which stones are still on the board and which are not.