Problem No. 120 from Igo Hatsuyoron
Created by Inoue Dosetsu Inseki (1646 - 1719)

Black to play and win
back to the Introduction


 What this problem is really about.
 Highlights (our key-results; highly recommended for a better overview).
 Main Path of the "official" solution in detail.
 Table "Main Path" (summary of the variations of the Main Path).
 Table "The second Throw-in" (summary of the results of our investigations).
 Several questions from 2007 (= the path to the Guzumi).
 Variations of the Main Path in detail.
 Variations after the second Throw-in in detail.
 Research on the move that probably solves the problem.

 TIME - what distinguishes between amateurs and professionals (or joins them together ?). THIS PAGE.

TIME - what distinguishes between amateurs and professionals.

... or joins them together ?

To have enough (what means a lot of) time seems to be the most important prerequisite if you want to work on this very complex and very complicated problem.

The Go World said that Shuko Fujisawa and his student's group needed more that 1.000 hours work to find the first solution.

Joachim Meinhardt was busy with the problem over years before he asked himself why not capturing the 20 Black centre stones with W 132 and playing the Oki of W 134 afterwards. And that revealed a blind spot of professionals.

I'm working on the problem since 2005.

It seems to me that time might perhaps be something being able to narrow the gap between amateur and professional strength a little bit. What seems to be very hard for professionals to accept.

I'll try to give some explanations below (based on my experiences with Yoon Sensei), combined with further insight into the problem.

Professionals "feel" the right move like greased lightning.

Dia. 10.1: "White's follow-up moves in the top left"

There are two types of White follow-up moves in the top left corner after "my" bad shape move of B 67.

White F, for example, is of the type that forces Black immediately to make two eyes for his large group in the upper right.

The second type consists of moves like White C. Hereafter Black must be at his guard and remember all the time that White could prevent two eyes for his upper right group.

Dia. 10.2: "Resistance in the top left is futile"

Black is unable to answer White 68 (= F) in the top left corner. White immediately will take Black's eyes in the upper right. You will recognize that the following "usual" cutting sequence in the centre does not work for Black any more.

Dia. 10.3: "White will lose after B 69"

During our investigations on moves of the second type like White C (= 68) we found out that it will be impossible for White to win if Black ever has got the chance to connect at F (= 69 - not necessarily at once). If White thereafter prevents Black's eyes in the upper right, it will soon be revealed that Black has won one tempo in the "usual" cutting sequence in the centre and the white stones on the left will die much faster than before. So White will be forced to capture Black's 20 centre stones, therewith losing the game.

This result was a very strong hint for us that it would be best for White to follow the proverb and take Black's most important point by herself.

Dia. 10.4: "What a professional feels within seconds"

When I asked Yoon Sensei what in her opinion would be the strongest move for White among A - I in the top left corner, she needed only seconds to answer "F" (= 68 here). We poor amateurs had spent several months work before to find this answer - and were not sure in the end about this.

"And how would White continue in the upper left after Black 69 on the right ?"

"W 70 - B 71 - W 72."

Three fast shots by Yoon Sensei, several weeks of thinking by poor amateurs.

Dosetsu's masterpiece forgives amateur's mistakes.

It seems to me that this problem is fault-tolerant to a certain extent.

Perhaps you remember that Yoon Sensei was so kind to help us with some Endgame sequences.

We amateurs had a lot of Endgame variations, which all had the same result of Black winning by a very small margin.

Yoon Sensei's Endgame suggestion is far more accurate than ours, takes into consideration aspects, I would never have dreamt of, and ended with the same result as our amateurish efforts.

So every of our mistakes must have been compensated by another one.

return to the top of page

The diagram-pictures were created with "SGF conversion" on Jan van der Steen's
Compiled by Thomas Redecker.

For a blog on East-Asian books on Go, please refer to Tchan001's Blog..

(c) DGoB -  letzte Aktualisierung: 2011-08-22 20:00,