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 Post subject: Review: The Endgame (Ogawa / Davies)
Post #1 Posted: Mon Aug 27, 2018 9:11 am 
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Review: The Endgame (Ogawa / Davies)

General Specification

* Title: The Endgame
* Author: Tomoko Ogawa, James Davies
* Publisher: Ishi Press (now: Kiseido)
* Edition: 1982 (2nd printing, brown cover)
* Language: English
* Price: EUR 16.50
* Contents: endgame
* ISBN: none (now: [?])
* Printing: good
* Layout: almost good
* Editing: good
* Pages: 211
* Size: 127mm x 181mm
* Diagrams per Page on Average: 3
* Method of Teaching: principles, examples
* Read when EGF: 10k - 3k
* Subjective Rank Improvement: -
* Subjective Topic Coverage: --
* Subjective Aims' Achievement: +

Preface

Although this is an old book first published in English in 1976, it is still sold because it is well-known and part of the Elementary Go Series. There are still only a few English endgame books so the book remains an option to be considered. My impression when I read the book as circa a 5 kyu is almost the same as when I reread it in 2018, 28 years later, as a 5 dan and endgame researcher, except that then it was the only English endgame book and now I can better justify my impression.

Overview

The book has five chapters. Chapter 1 uses one game to introduce the endgame informally. The game comments are mostly uninteresting descriptions ("White 38 threatened an invasion of the upper right corner again, so I defended at 39.") but interludes prepare the reader softly for the next chapter, show variations of enclosure josekis, which a reader of expected rank may find useful, or give a sample illustration of counting territory during the game. For that purpose, the diagram annotation is a bit strange: for the sake of counting in pairs, two adjacent intersections carry the same integer.

Chapter 2 is the core of the book. It explains evaluation of moves of local endgames. First, some theory is explained shortly. Second, nine problem diagrams each with three local endgames, a few answer diagrams and one combination diagram per problem train application of the theory. Apparently, the combination diagrams presume an unshown whole board context during the early to intermediate endgame, where the three local endgames must be played first in their correct move order.

Chapter 3 shows a good variety of the most basic endgame tesujis and a few problems for each type. If you have not seen the monkey jump or other tesujis of a comparable, basic level before, the chapter should be useful.

The macroendgame (transition from the late middle game to the early endgame) is the topic of chapter 4. There are nine whole board problems each with five moves to choose from. The answers are short. That is all. Chapter 5 is similar but shows two games during the intermediate endgame, each with ten problems and multiple choice among three candidate moves.

Except for the interludes in chapter 1, the chapters 1, 4 and 5 are mostly filling material trying to compensate the too short theory in chapter 2. In particular the macroendgame would have deserved general theory and at least careful approximative calculations of the move values of the top two candidates. Instead, we mostly get disappointing informal text, such as "Although tbe continuation is a bit difficult, there is no question that Black 1 is the right move".

The Theory

Chapter teaches move values of gote, sente, reverse sente and double sente for traditional endgame theory, where you multiply by two for playing in sente or reverse sente to compare with playing in gote. The book compares "Black goes first" and "White goes first" but avoids a term for the calculated difference value. It compares the two resulting local positions but avoids terms for them (nowadays we call them black and white follower) and the counted value (we would call them the count). It counts locally but does not explain the concept of locality (which I would call the locale). It studies follow-ups but avoids this term like the plague. To calculate the impact of a follow-up on a move value, it sometimes considers the white follower's white follower or the black follower's black follower but, as we know, avoids these terms. Instead, it uses various, confusing, informal descriptions for the same term, concept or value. The reader must enlighten himself. Likewise, the book describes newly acquired values by different phrases with a preference for "to gain". As a consequence, the author herself lacks a clear understanding and sometimes makes the mistake of adding gote and sente gains without first calibrating such different values.

Furthermore, the book tries to simplify. It approximates by rounding to avoid fractions and prune the impact of iterative follow-ups on move values. Although this works for the simple examples in the book, this also means that the reader does not learn determination of move values of local endgames with intermediate to large iterative follow-up positions. The book speaks of average, mathematical average or mean (all meaning the same) but does not explain how to calculate an average. For the simplest calculation, the calculation shown multiplies a value by 1/2, puts this in brackets and adds this to some previously calculated value. Otherwise, the book avoids brackets for arithmetic. It invents, however, a creative alternative use for brackets to indicate a rounded value as being slightly smaller, such as "5(-)", or larger, such as "5(+)", than an integer. It also avoids negative numbers but speaks of White's points. This may work for the simple examples of the book, but the reader does not learn proper calculation in general. Funnily, the book cannot quite admit to avoid negative numbers when writing "the total difference is 1+1=2 points". If White's points were accounted properly as negative points, we would indeed have the difference "1 - (-1) = 2". After dissolution of bracket and minus signs, this becomes the sum stated in the book.

Does the reader profit from all those attempts of simplification? Hardly. Besides the few principles hidden in ordinary text, he has to make sense of several different methods of how a gote follow-up is calculated. Sometimes it is the average of two numbers, the average of one number (and - not declared by the book - the number zero), derived from the white follower's white follower and an average, or derived from the black follower's black follower and an average. Without the underlying theoretical explanations why each method works and produces correct move values, it can be hard to understand everything while overcoming confusion.

At least, the move values in the book are correct if we tolerate approximations. Sometimes the author was lazy and an approximation is correct only plus-minus 2 points. The explanation of theory for sente, reverse sente and double sente is even shorter. The relative value of sente or reverse sente are explained by an argument fitting modern endgame theory: points per difference in the numbers of played stones. Unfortunately, this is the only aspect of modern theory in the book.

More confusion arises when gote and gote (or sente and sente) have different meanings. Either word might refer to the type of local endgame or to the kind of sequence but the book never says "gote sequence" or "sente sequence" when it means such. The reader must always disambiguate the context, especially when both contexts occur in the same sentence. Worst of all, we learn that a reverse sente "is gote". What this means is that a move played in reverse sente starts a gote sequence. Such problems occur when a book does not properly introduce the basics and avoids by far too many terms, which would clarify everything.

Not surprisingly, the book introduces double sente as "either side can play in sente", means local double sente and is unaware of its inexistence. As a consequence, the answers to the problems calculate move values in double sente even when the most obviously the follow-up threats are too small by far. In the most obvious example, the author noticed this by herself ("Black 1 is not necessarily sente, either.") but did not draw the right conclusion. The harm from this conceptual mistake is limited though because the book offers useful practical advice for when to play double sente.

From the theory and problems in chapter 2, the reader learns calculation of move values of gote or sente without follow-up. Hardly from the theory alone - but from the combination of theory and problems. Learning reverse sente is made more difficult. Maybe the bright reader also learns calculation of a move value if the local endgame has simple, direct follow-ups. However, calculation of a move value is peculiar in the book: only intersections of either player's territories with changes are counted by mentally comparing two diagrams. This works for the simple examples in the book but the method might fail for more difficult examples.

The Missing Theory

Endgame evaluation in the book misses the following theory: in general exact move values instead of approximations, move values of local endgames with iterative follow-ups and larger impact than rounding approximations, a careful explanation of the basics, basic terms, basic concepts other than move value, count of an initial local endgame, counts of followers, evaluation of ordinary kos or ko threats, gains (when Black's and White's moves gain different amounts not both described by the move value), net profit, theory relating the different values, careful study of different kinds of follow-ups, modern endgame theory, microendgame, area scoring, a clear distintinction of sente and gote, ambiguous local endgames, evaluation of long local sequences, value theory for move order during the early and late endgames, advanced theories.

Conclusion

The book is written for beginners of endgame theory. Apart from the additional chapters, it only touches the only one aspect of move value. The unclear, confusing presentation with countless omissions especially of basic descriptions make good understanding of the contents unnecessarily hard especially for the intended readership. Theory and didactics of the book are outdated.


Disclaimer: Robert Jasiek is a researcher in the endgame and other go theory, author of endgame books and other go books, and go teacher.


EDIT: add disclaimer


Last edited by RobertJasiek on Mon Aug 27, 2018 11:19 pm, edited 1 time in total.
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 Post subject: Re: Review: The Endgame (Ogawa / Davies)
Post #2 Posted: Mon Aug 27, 2018 11:07 am 
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I find trash talking a rival book under cover of a review to promote your own book rather distasteful.

As it happens, I too found the Ogawa/Davies book disappointing, so I am not defending it per se. I just find the circumstances a bit stinky.


This post by John Fairbairn was liked by 3 people: asura, bernds, Javaness2
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Post #3 Posted: Mon Aug 27, 2018 12:05 pm 
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If you find any mistake in the review, discuss it. If you don't, don't call it trash talking.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies)
Post #4 Posted: Mon Aug 27, 2018 4:53 pm 
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Hi Robert!

I haven't read any of the books (but read both of your reviews).

Considering your position as author of a competing book, and as such, being potentially financialy biased in your reviews, you should at the very least add a disclaimer at the top of your review to explain the situation (with maybe a link to your other review).

Really, this is just good practice, even in science.

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Post #5 Posted: Mon Aug 27, 2018 9:41 pm 
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Thank you for your suggestion, but if I add something like "Disclaimer [of possible conflict of commercial interest]: I have written other endgame books [and write more].", doesn't this sound more like an unnecessary advertisement at an inappropriate place than a disclaimer? I can add a disclaimer, but what should it express? It could be extended to mention being an endgame researcher already in the disclaimer instead of the review.

On a related topic, in this review I have avoided discussing the impact of this book and similar books on my own development of endgame skill as a player and everybody's such development. In my recent self-review, I have mentioned my opinion of the impact: after learning something about the endgame at all, I think that the limitations of such books have greatly delayed further development of endgame skills. Shouldn't I also add a disclaimer that the review is not as critical as it might be because of not addressing this impact?

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Post #6 Posted: Mon Aug 27, 2018 10:32 pm 
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I looked at Ogawa/Davies not long after it came out. Along with Kano's Yose Dictionary it was one of the first endgame books to question the idea of double sente, while not yet able to reject it. Ogawa and Davies pointed out that double sente implies division by zero, which does not make sense. :)

Like just about every pro authored endgame book before O Meien's recent text, it contained cringeworthy calculations.

----
Edit:

I suppose that I should also mention that I am an endgame researcher and author of academic articles on the mathematics of the endgame. :)

I have an interest in Robert's new book, although not a financial one. This year he showed me part of his draft, and I offered some remarks. He has sent me a complimentary copy of his book.

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Last edited by Bill Spight on Mon Aug 27, 2018 11:03 pm, edited 1 time in total.
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Post #7 Posted: Mon Aug 27, 2018 10:41 pm 
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I do think that it would have been appropriate for Robert to mention that he is an endgame researcher and author of endgame books, as well as other go books. The reader can draw her own conclusions about his motives and expertise.

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Post #8 Posted: Mon Aug 27, 2018 10:59 pm 
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Quote:
double sente implies division by zero, which does not make sense. :)
Hi Bill, would it possible for you to elaborate a bit on double sente ? ( Or maybe it's covered at Sensei's somewhere ? ) Thanks. :study:

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Post #9 Posted: Mon Aug 27, 2018 11:15 pm 
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Bill Spight wrote:
I do think that it would have been appropriate for Robert to mention that he is an endgame researcher and author of endgame books, as well as other go books.


Ok, this sounds like a reasonable style of disclaimer and resembles typical remarks in newsjournals or scientific texts, as I have seen them. I will add some such disclaimer soon. As far as I have seen them, such disclaimers tend to occur after a text, therefore this will be the place where I put my disclaimer.

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Post #10 Posted: Mon Aug 27, 2018 11:56 pm 
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EdLee wrote:
Quote:
double sente implies division by zero, which does not make sense. :)
Hi Bill, would it possible for you to elaborate a bit on double sente ? ( Or maybe it's covered at Sensei's somewhere ? ) Thanks. :study:


I have written about double sente on SL and here. Let me offer some brief remarks here. See, for instance, these threads.

viewtopic.php?t=11129
viewtopic.php?t=11134
viewtopic.php?t=11167
viewtopic.php?t=11149

Also, these discussions:

viewtopic.php?p=223244#p223244
viewtopic.php?p=194476#p194476

Many moons ago I submitted an article to the Go World magazine claiming that there is no such thing as double sente. I have since changed my mind. Like nearly every word, sente and gote have acquired different meanings. There are plays such that, on a given board, correct play is to answer them, regardless of which player makes them, and corresponding local positions. Whether to answer them depends upon the rest of the board. They are double sente on that board.

However, there is a sense of sente that does not depend upon the rest of the board, which we use when we evaluate positions and plays. There is a similar sense of gote. Let me call these intrinsic sente and gote.

It is possible for a play to be intrinsic gote and yet be sente, or even double sente, on a particular board. As I now see it, one problem with traditional endgame texts is that they confuse these different senses of sente and gote. They pass this confusion on to players. That certainly happened to me. ;)

Edit: In particular those books present local positions and call them double sente. That's just wrong.

Even worse, at least one book presents a whole board position with several so-called double sente and shows sequences for each player where that player gets to play all of those positions with sente, so that the resulting difference between the results when Black plays first and when White plays first is huge. And wrong. :roll: :mad:

Edit 2: Ah! I found this post, which shows the offending position and play, along with a position where the professional authors got it right. :)

viewtopic.php?p=194535#p194535

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Post #11 Posted: Tue Aug 28, 2018 6:09 am 
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I have read this book at least five times and I think it is a good book. Everyone, who has not studied endgame so far, will surely profit from reading this book. This is a go-book and no math-book (like the book Robert Jasiek just wrote), but it teachs all the math you need to evaluate the positions.
It strikes a good balance betwwen practice and theory. I think you can easy improve yor endgame by 10 points whith this book.

It seems to me, that Robert Jasiek does not really understand the concept of deri-counting, but once you understand it, it will become clear that there are many situations when this way of counting is more easy then miai-counting. And of corse, you will get the same answer with both methods.
(You could compare deri-counting vs. miai-counting with probability calculation, where you could write the chance to roll a six with one dice is 1/6. You could also write 16.67%. Yet another way would be 1:5 (one six and five times no six), but the confusion could start when someone will treat ":" and "/" the same and write f.e. 1:6 instead of 1/6. When you understand these concepts you will realize, that depending on the question you have, in some calculations one way of representation will be more comfortable.)

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Post #12 Posted: Tue Aug 28, 2018 6:22 am 
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I am a small sample myself but I liked Getting Strong at the Endgame much better than Ogawa's book. Ogawa's book is neither theoretically well grounded nor very practical. GSatE is very practical, with its many exercises and the quiz fore & aft.

From analyzing pro games I learned that the endgame is all about sente and sente is all about life & death.
As a rule of thumb, taking all your big sente (the small ones are ko threats) first, then the biggest gote, is good enough.
The concept of reverse sente is almost meaningless and when I read about it in Ogawa's, it confused me.

Precise counts are great for encycopedeas, in actual play the technique costs too much time. On the other hand, a fighting spirit principle like "mutual damage" is very practical.

Oh, and Robert has all the rights to review competing books: he reviews his own too. :)

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Post #13 Posted: Tue Aug 28, 2018 6:27 am 
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Bill Spight wrote:
There are plays such that, on a given board, correct play is to answer them, regardless of which player makes them, and corresponding local positions. Whether to answer them depends upon the rest of the board. They are double sente on that board.


Which means that the result is independent of that play and so one player has an advantage bigger than the local count. Which means that the other player has made a big mistake already.

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Post #14 Posted: Tue Aug 28, 2018 7:27 am 
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Knotwilg wrote:
Bill Spight wrote:
There are plays such that, on a given board, correct play is to answer them, regardless of which player makes them, and corresponding local positions. Whether to answer them depends upon the rest of the board. They are double sente on that board.


Which means that the result is independent of that play and so one player has an advantage bigger than the local count. Which means that the other player has made a big mistake already.


Then I have expressed myself poorly. In real games, many double sente are ephemeral, arising in a sequence of elevated temperature. Nobody is going to tenuki, and so they get played and answered right away. Usually nobody gives them a second thought.

Sometimes they can stay on the board a long time. That can happen when the time to play them is right before a temperature drop. For instance, suppose that there is a gote that gains 5 pts.; if Black plays it, White's response gains 4 pts.; if White plays it, Black's response gains 3½ pts. Suppose that the current temperature is 7 pts., so no one makes that play yet. When the temperature drops to 5 pts., someone does. But then there is a drop in temperature to 3 pts. on the rest of the board. Then the play will be double sente. (As a rule, OC. :))

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Post #15 Posted: Tue Aug 28, 2018 7:44 am 
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RobertJasiek wrote:
Ok, this sounds like a reasonable style of disclaimer and resembles typical remarks in newsjournals or scientific texts, as I have seen them. I will add some such disclaimer soon. As far as I have seen them, such disclaimers tend to occur after a text, therefore this will be the place where I put my disclaimer.

Quote:
Disclaimer: Robert Jasiek is a researcher in the endgame and other go theory, author of endgame books and other go books, and go teacher.


Yep, this is a fair enough disclaimer :)

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Post #16 Posted: Tue Aug 28, 2018 7:59 am 
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asura wrote:
I have read this book at least five times and I think it is a good book. Everyone, who has not studied endgame so far, will surely profit from reading this book. This is a go-book and no math-book (like the book Robert Jasiek just wrote), but it teachs all the math you need to evaluate the positions.
It strikes a good balance betwwen practice and theory. I think you can easy improve yor endgame by 10 points whith this book.


Anyone who hasn't paid attention to endgame will surely profit from reading any endgame book. I own this book, as well as get Strong at the endgame and Yose (French book by Motoki Noguchi and Dai Junfu). I would recommend those two over The endgame. I haven't read any of Robert's books about the endgame so I can't compare.

Quote:
It seems to me, that Robert Jasiek does not really understand the concept of deri-counting, but once you understand it, it will become clear that there are many situations when this way of counting is more easy then miai-counting. And of corse, you will get the same answer with both methods.
(You could compare deri-counting vs. miai-counting with probability calculation, where you could write the chance to roll a six with one dice is 1/6. You could also write 16.67%. Yet another way would be 1:5 (one six and five times no six), but the confusion could start when someone will treat ":" and "/" the same and write f.e. 1:6 instead of 1/6. When you understand these concepts you will realize, that depending on the question you have, in some calculations one way of representation will be more comfortable.)


Saying Robert doesn't understand the theory is a very bold statement. I'm tempted to buy his book but I'm much more worried about seeing too much theory and not enough practical advice.

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Post #17 Posted: Tue Aug 28, 2018 8:21 am 
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explo wrote:
Saying Robert doesn't understand the theory is a very bold statement.

Nevertheless it's true when it comes to applying the deri-method. (I also said "it seems"... I have no idea if he doesn't understand it or if he just pretend so.) Else there wouldn't be such statements like
RobertJasiek wrote:
Funnily, the book cannot quite admit to avoid negative numbers when writing "the total difference is 1+1=2 points". If White's points were accounted properly as negative points, we would indeed have the difference "1 - (-1) = 2".


In many situations, the deri-counting-method is just more comfortable to use than the miai-counting-method. As a mathematician I do not say one method is better than the other, but I say, it depends on the question you want to solve, so I would recommend to know (and use) both concepts, because then you can choose the most easy way in different situations.

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Post #18 Posted: Tue Aug 28, 2018 9:18 am 
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asura, there is no doubt that somebody knowing close to nothing about the endgame profits from the book to some extent (as you say, surely 10 points). The problem is not that the book would be useless but that it wastes very much potential for improvement. When I first read it, I had known close to nothing about the endgame and the book improved my endgame by a couple of points, say 10+. However, some 10 points are almost nothing compared to the huge amounts I must have lost during the endgame as circa 5 kyu.

I would not really understand traditional endgame theory (deiri counting)? There have been different stages of my understanding of it during the previous 28 years.

Stage 1 (1992, 5 to 3 kyu): I had mostly Ogawa's book as a source, calculated deiri move values of gote, sente and double sente without follow-ups reasonably but with many mistakes, made more mistakes with reverse sente, did not clearly understand that dead stones were worth 2 points because the book creates extra confusion for that (speaking of 3 prisoners when referring to 3 dead stones being worth 6 points), had great trouble calculating move values of local endgames with direct follow-ups and do not recall to have ever calculated local endgames with iterative follow-ups then. I was not aware of other aspects of endgame evaluation.

Stage 2 (1992 - 1997, 2 kyu - 4 dan): like stage 1 but I knew that dead stones are worth 2 points. I learned this as a consequence of rules study, when comparing the scoring systems.

Stage 3 (1998 - 2016, 5 dan): Additional endgame books (Get Strong at the Endgame, Japanese / Korean endgame problem books) and tesuji books improved my endgame tesujis but had almost no impact on my calculation of deiri move values. Bill Spight's online discussions about the endgame had the side effect that I calculated more local endgames with follow-ups and slowly learned iterative follow-ups. However, I mostly roughly guessed move values when iterative follow-ups were involved because a clear, easy description was missing everywhere. I became aware of the existence of modern endgame theory (miai counting) but neglected its study for a long time because discussion focussed on expert aspects (such as infinitesimals and temperature) for which I saw too little practical use in comparison to the learning effort. Most of the books on traditional endgame theory had lots of mistakes in their move value calculations and lazy rounding everywhere. So I still used traditional endgame theory only for move values but by 2016 I had finally understood the basics of modern endgame theory beyond the fragments of it appearing in my earlier books, when useful also for non-endgame theory. Methods like the Unsettled Group Average forced me to acquire a basic understanding.

Stage 4: (autumn 2016): I spent a few months of reading every online message and webpage I had collected over the years to identify everything relevant, organise it and raise my understanding of modern endgame theory to a level necessary for book teaching. A new wave of discussions with Bill started and I realised that his research touched huge gaps in endgame theory. To fill them, I joined research.

Stage 5 (late 2016 - 2018): I wrote Endgame 2 - Values while researching in the practically relevant aspects of modern endgame theory and constantly improving my understanding of it. As a byproduct, my understanding of traditional endgame theory applied those aspects of modern endgame theory applicable under both: especially the counts of positions and followers. My description of traditional endgame theory is short but more detailed than I have seen anywhere else because everywhere else often only deiri move values are explained. As a consequence of writing and researching, I can now calculate local endgames with follow-ups under both theories. I had bought Mathematical Go Endgames in 1994 but understood almost nothing until rereading it several times while writing the book. Surprise - it is related to modern endgame theory.

There is no such thing as endgame calculation without arithmetics. Ogawa' book uses mathematics, my book does and Mathematical Go Endgames does. All are go books, but I would only call the latter also a maths book. The books use mathematical annotation to different degrees of formalism and mathematical tools. Ogawa restricts it to 2+(1/2*5) = 5(-) while pretending successful hiding of negative numbers and fractions other than 1/2. My book also uses negative numbers, brackets, variables and unequations, that is, school mathematics. This does not make it a maths book but a book in which necessary calculations are being done and formulas represent the same calculations in general, except that we insert the actual values of an example. Mathematical Go Endgames uses mathematical annotation as it might appear in a mathematical research paper, such is a maths book. My planned Volume 6 will be a maths book with mathematical proofs but go players need not read it to understand the applied school maths in the earlier volumes.

There is only one noteworthy kind of evaluation when deiri counting is easier than miai counting: if gote move values are compared to gote move values and NOT compared to move values of other types. (You speak of many situations, but it is only this kind of situation and not the many situations of other kinds.) When sente move values are compared with each other only, or gote or sente counts are calculated, deiri and miai counting are equally easy. For every other purpose, miai counting is EASIER. For many purposes, deiri counting makes no sense at all, unless first we transform its move values to miai move values. E.g., it is easier for comparing gote to sente move values or evaluating kos. E.g., deiri counting makes no sense when evaluating the impact of a gote move expressed by its move value on the value ("count") of a position.

For applications where both methods are applicable, we get the same answers. For applications where deiri counting is inapplicable, we do not get an answer for deiri counting or get a wrong / meaningless answer.

In my games, I apply both methods. When deiri counting is more convenient (for only comparing gote with gote move values earlier than during the microendgame), I use it. When both are applicable equally conveniently, I use either. When only miai counting is applicable, faster or precision is needed, I use it.

Since both methods have their uses, my book explains both. Since only miai counting is consistent and naturally allows value relations and advanced uses, the book explains miai counting in much greater detail. This makes perfect sense because deiri counting falls apart for everything but the few most basic applications. One must not put too much faith in a method whose application is already so cumbersome for ordinary kos that the literature is full of bad explanations, mistakes or (as in the case of Ogawa's book) a failure to explain ko at all.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies)
Post #19 Posted: Tue Aug 28, 2018 9:37 am 
Tengen

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asura wrote:
Else there wouldn't be such statements like
RobertJasiek wrote:
Funnily, the book cannot quite admit to avoid negative numbers when writing "the total difference is 1+1=2 points". If White's points were accounted properly as negative points, we would indeed have the difference "1 - (-1) = 2".



Ogawa's book writes difference when it calculates the sum. The mistake is hers, not mine. I understand her thinking though because it is tempting to replace double negation by a plus sign (too) quickly.

If you study deiri counting carefully, you will encounter the positions with the necessity for expressing W points by negative numbers and comparing the B and W followers by forming the difference (value, swing, deiri value calculated as a difference). This then becomes the calculation that always works.

Only positive numbers and sum do not do it in general, although some authors pretend so. In particular, a settled black follower or a settled white follower can have changes of B and W territories, of which EITHER might be larger.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies)
Post #20 Posted: Tue Aug 28, 2018 9:44 am 
Tengen

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explo, "worried about seeing too much theory and not enough practical advice":

you might wait for Volume 4 and then worry about the converse:) Volume 2 is the theory book, Volume 4 will be the problem book and both together provide both. OTOH, you are in France and might find the chapter about area scoring useful if you attend French tournaments.

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