[Welcome to Sensei's Library!]

StartingPoints
ReferenceSection
About


Referenced by
Shicho

 

Longest Ladder Problem
  Difficulty: Advanced   Keywords: Problem, Life & Death

[Diagram]
Diag.: White to play and capture the marked stones.

jvt: (First try). This long spiral (321 moves) is the longest ladder (without ko) I can imagine.


[Diagram]
Diag.: White to play and capture the marked stones.

No shicho ?

jvt: Well, if White does not want to play the nice spiral... :-)



Not only can White resolve the spiral early, but also Black will sacrifice the corner stones and kill White. It is not that I refuse to be a good sport, but IMHO the real challenge is to find a gigantic Shicho which does not depend on the benevolence of the two players.

--DieterVerhofstadt


All right. It should be possible to tweak the above problem a little to force White to play atari all the time. Some White stones need to be in danger in the corner, so White can't afford to play any other move than atari. The difficulty is to make the capturing sequence at least 300 moves long.

What about this? 306 moves.

Note: If Black doesn't play at 1, he looses the semeai anyway.

--jvt

[Diagram]
Diag.: White to play and live.


This is a copy of the living page "Longest Ladder Problem" at Sensei's Library.
(C) the Authors, published under the OpenContent License V1.0.