Monday, January 11, 2010

Tsumego (14): Answer

Here is the answer for tsumego 14

After white connects, black can tries to attack white's marked group, but it's actually a mistake.
it's a mistake.

Black plays a forcing move with 2. White defends with 3. The semeai continues, but white combination at 5 and 7 makes
black lost the semeai by 1 liberty.

Even if black tries to follow the rule of semeai ("Create eye(s) when semeai") won't work, since she'll still lost by 1 liberty.

The answer for this tsumego is ko fight. Black cuts at L18. White answers with 2, avoiding atari. Black plays another atari with 3. Black answers at 4.
Black can't play 4 at N19, since the ko fight will be clearly favorable for black. Black continue by creating a ladder with 5 and white avoid by 6. Black play 7 to stage a ko fight.
White takes first, then black plays 8 as a ko threat. White defends with 9 to avoid losing his group, then black retake the ko with 11. The game continues with 12 and 13, then white retake the ko.
Black plays at 15 as a ko fight. White can still continue the semeai by playing 16. Black retake the ko. White plays 18. Black defends. White retake with 20. Black attacks the white's group with 21.
White can try to kill black's big dragon, but after black retake the ko, white will run out of ko threat and black alive.

The problem came from 43rd Korean Kuksu, winner group final between Lee Changho (white) vs. Rui Naiwei (black).