Endgame Test One - Solution 3
Difficulty: Expert
Keywords: EndGame, Problem
More analysis of "The Practical Endgame Test One".
Solution is White wins by 4 points - find it at Endgame Test One Solution.
![[Diagram]](../../diagrams/38/daf95b329a195ca3e9d260835e12d996.png) | Can Black keep the margin to 3? |
When Arno posted this position, I became fascinated by the question can Black force a better result than W+4?
It took me a long time to think that I found the answer...
--DaveSigaty
![[Diagram]](../../diagrams/12/893f3e6a91bb2ef15ae7202e8feeeb68.png) | Variation 1 |
Black plays because otherwise White's play at b is too damaging. White then goes back to , giving Black the chance to capture at . If White now plays on the left, Black plays forcing . White can not ignore because Black at followed by descending to the edge is a very big play (even bigger than capturing the stones if White plays at d instead of ).
On the left side, Black at is the right way to play. When White cuts at it is worth 2 points for Black to ensure an eye on the left side. Otherwise he will have to play another stone on the right to prevent White's atari at c.
![[Diagram]](../../diagrams/37/e26ee2b9d1cda0522e00ea7762c9e8b5.png) | W+3 |
Black has two poins on the left and 10 points on the right.
White has four points at the bottom and 11 points at the top.
White wins by 3 points.
(NB: don't forget to count the captured stones.)
![[Diagram]](../../diagrams/35/f1049f107b5799a82312fe6225d0e8dc.png) | Variation 2 |
White can try blocking at , knowing that she can win a ko fight. However, Black does not need the ko to improve on the solution diagram...
![[Diagram]](../../diagrams/1/b841f3633a4485f7e97dcb39da3844a8.png) | Imperfect reversion |
Now note that if White captures at a and connects, we have reverted to the solution diagram except that has been added inside White's territory. In addition each side has captured one stone near a but they offset each other. Final result? W+3.
![[Diagram]](../../diagrams/39/96e4bf03a0f0bce1ac1f3686b5a521c0.png) | Variation 3 |
White plays after reading out that she can't let Black capture here. However, is a big play with the follow-up at as absolute sente. Play continues to but White's winning margin has been reduced to a single point.
To summarize: if White plays in the first diagram
Black can force a three point loss, instead of the four point loss in the correct solution.
This is a copy of the living page
"Endgame Test One - Solution 3" at
Sensei's Library.
2004 the Authors, published under the OpenContent License V1.0.
|