Source:
Problem diagram.
Black plays in the lower left.
Segoe Kensaku & Go Seigen, Ishi Press
Solution follows
(or click here to download SGF)
Correct.
A play at 1 is the only move if Black is going to capture something.
And a play at 2 is the only move if White is going to save his stones.
The sequence to 4 is forced for both sides.
Black's 2 stones only have 3 liberties, so Black must reduce White's liberties faster than that!
See the next diagram for the follow up.
Continuation.
Black 5 is the only move, but White 8 appears to have won the semeai.
White has 3 liberties and threatens to capture a stone.
But Black has a resource!
Black 11 catches White in a shortage of liberties. Black wins the semeai.
Black variation.
Black 5 is too slow.
After 6, White has more liberties than Black's 2 stones, so Black loses the semeai.
Email the Problem Of The Week editor at potw@usgo.org
Hits: 990