Review: The most difficult problem ever / Igo Hatsuyoron 120

    Title: The most difficult problem ever / Igo Hatsuyoron 120

    Author: Thomas Redecker

    Publisher: Brett und Stein Verlag

    Edition: 2011

    Language: German + English

    Price: EUR 15

    Contents: tsumego

    ISBN: 978-3-940563-18-7

    Printing: good (very good in relation to layout + paper)

    Binding: rather weak

    Layout: good (but small diagrams + bilingual)

    Editing: good

    Translation: good

    Publisher's Choice: doubtful (too few pages to reduce price)

    Pages: 140

    Size: 168mm x 220mm

    Diagrams per Page on Average: 3

    Method of Teaching: (mostly) examples

    Read when EGF: 7k-7d

    Subjective Rank Improvement: -

    Subjective Topic Coverage: -- (tsumego in general) or + (the

specific problem)

    Subjective Aims' Achievement: ++

Probably Igo Hatsuyoron is the most difficult classical problem

collection, was compiled by Dosetsu, started as secret study material

for a few first class players and is said to have been written in

1713. The whole board problem 120, which is the book's only topic, was

rediscovered by Araki Naomi to be published in 1982 by Fujisawa

Hideyuki (Shuko) 9p. This problem is the by far most difficult

classical tsumego problem but the book title overlooks more difficult

non-tsumego problems. The problem is so difficult though that some

thousands of manhours of research have not proven a solution yet. The

book presents a new solution but problem solving consists of another,

here still missing step: the verification beyond doubt (when the book

says "professionally confirmed", then that is also insufficient).

Thousands of already studied variations are necessary but

insufficient; there needs to be complete logical linking between all

of them on a level above trivially immaterial variations. This,

however, is not easy because #120 requires interesting subtrees

starting from counter-intuitive, partly bad shape plays. On the other

hand, the book's solution seems to be the currently by far best

understanding of the problem.

Maybe the problem remained hidden for centuries because editors

suspected a mistake in the problem position and could not discover its

central topic. Modern study of the problem started with 1,000 manhours

by Fujisawa and his study group to reveal that topic: a hane-seki with

a 20 stones tail in the board's center. To 1988, Cheng Xiaoliu 6p

worked on the endgame and later continued partial studies. In 2005

Joachim Meinhardt 5k, in 2007 Yamada Shinji 5p, in 2007 Thomas

Redecker 1k, in 2009 Harry Fearnley 2d and during the years to 2011

mainly the study group of the three mentioned amateurs found new

plays, researched their consequences and developed the book's solution

with occasional professional hints. Professionals started but

amateurs, who have now invested some thousands of manhours, have taken

the lead in the race towards a final solution.

While Redecker's manuscript Igo Hatsuyoron Problem 120 / The most

difficult problem ever of 2009 had no binding, weak layout, worse

language and hard to follow contents, the reviewed book makes great

efforts in teaching the problem's structure, timing of moves, global

relation of local status and decisions, history of the problem's

research and a few fundamentals of approach liberties, regular and

circular hane-sekis. While the first half of the book has sufficiently

many variations, the second half's study of recent discoveries shows

too few representative variations and points to webpages. Despite this

unfortunate restriction by the publisher, the reader can follow what

this problem is all about and where current research resides.

Nevertheless, I expect having to read the book thrice to really

understand all the contents, each play and its correct timing in each

variation and the long term impact of some plays with peculiar timing.

Whoever would want to join the study group must also read over 1,000

variants on webpages and ask for any most recent variants. The

ordinary reader will be happy to get at least a good overview on the

problem from the book.

So what happens in the problem? Imagine four difficult problems, one

in each quarter of the board. Each is about tsumego, life and death

and endgame and each has its spectacular aspects. For example, the

hane-seki is not ordinary but has two additional groups and many

global side effects for cutting problems, life and death and endgame

in the other parts of the board. The exact position of each stone on

the board matters and the interdependence of shapes and variants

creates an extraordinarily complex whole board Black to play and

possibly win problem. The various parts and aspects are so well

integrated to each other that it is hard to believe in coincidence.

Dosetsu's knowledge must at least have anticipated today's partial

solution knowledge. Presumably he spent years on creating the problem.

This makes it an artful masterpiece and celebration of the human mind.

We play Go because we admire such great depth and skill.

Of course, nobody needs a book on just one problem and being not

particularly suitable for rank improvement. One can also criticise one

or another detail like a missing note in the legend whether captured

stones count at the beginning or end of a diagram's variation. Such

misses the point. The book, and especially for its price, is one of

the first choices among the appreciation type of Go literature and

furthermore evidence of the growing power of Western amateur research.