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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #21 Posted: Tue Aug 28, 2018 10:14 am
 Honinbo

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asura wrote:
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.

As a mathematician, you may be unaware of how even good players who only know deiri counting misunderstand and abuse it. (Those who know both deiri and miai counting are less likely to do so.)

Here is a simple example. Suppose that such a player accurately counts the game and finds that White is 3.5 points behind. He also sees that there are only a few gote left on the board, the largest of which is worth 5 pts. (by deiri counting, which he thinks is the only kind). He erroneously thinks that White, who has the move, has a chance of winning (Edit: with correct play, OC).

Here is another example from real life. I don't remember the exact details, but a 5 dan who was also a computer scientist proposed something like this. Suppose that we have a 4 pt. sente with a simple threat worth 10 pts. (all by deiri counting). We multiply the sente value by 2 to get a value of 8 pts. Then we add the values together to get 18 pts. Then, since there are three plays involved, we calculate the gain for each play by dividing by 3, so the sente play gains 6 pts.

Then there are people who think that because you multiply the value of a sente play by 2, you should multiply the value of a double sente play by 4.

The problem is people who think that they understand deiri counting, who don't.

----

Edit: Over 20 years ago I went on a crusade to introduce miai counting to the West, since hardly anybody was aware of it, and there was much confusion because they thought that deiri counting meant something that it does not. After some time, I came to believe that I had not dispelled much confusion, but perhaps even introduced confusion, leaving people with two methods of evaluation, neither of which they understood. So now I avoid talking about the two methods, and simply talk about how much a play gains on average. People who just want to compare plays can use deiri counting, but those who want to know how much a play gains can figure that, as well. O Meien did the same kind of thing in Japan, calling his method Absolute Counting. (It's really miai counting. Good PR, I suppose. )

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Last edited by Bill Spight on Tue Aug 28, 2018 11:02 am, edited 1 time in total.
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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #22 Posted: Tue Aug 28, 2018 10:51 am
 Gosei

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Robert's book started my interest for miai counting. I always were on the lookout to compare endgame moves more exactly. It explains modern endgame theory very detailed.

I think my first step is to memorize the miai counting shapes on sensei. Many moves I categorized already correct by intuition. But now I understand the miai values of the moves and have therefor a tool to get a finer grasp on the different size of endgame moves.

I am also now able to calculate the miai value for shapes that I have not memorized.

I am very thankful to Bill and Robert for their endgame studies.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #23 Posted: Tue Aug 28, 2018 11:36 am
 Oza

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For amateurs, and it would seem pros, boundary play theory as exemplified by Robert is massive overkill, and has more to do with mathematics than go.

The very fact that it is difficult to trace thinking about boundary plays in the Oriental literature tells us a lot about the proper priorities. We know that de-iri counting was known before 1844, because that was when Genan published what he claimed was the first book on counting boundary plays. He did not use the term de-iri, which may not have been used until the early 20th century, and he did not claim to have invented the concept (despite being brash enough to publicise himself) and he did not feel the need to explain the counting method. All this strongly suggests the method was already well known then, and since the endgame play of Edo players is regularly praised even today we may safely assume it already had a long history. That is, there had already been ample time for refinements to emerge.

But when we look at Genan's work (which I have long made available in the New In Go package that comes with the GoGoD database), we see the rather simplistic model that we are familiar with even today. Genan essentially uses three criteria to evaluate a boundary play: de-iri points, sente/gote, and (as an optional third element) incidentals such as aji, ko threats.

Nowhere does he speak of double sente or reverse sente, but he clearly understood at least some of the niceties of the term sente that Bill regularly refers to. For example, at one point he says a move is "worth about 9 points and can be regarded as sente" (my emphasis).

A few times he does occasionally mention half-point fractions, but feels no need to go into sixteenths and so on, and usually he is satisfied to say a play is worth "about" X points. This very simple model was clearly all that the Edo masters needed, and over the many years since then it has become apparent that it was sufficient for generations of later pros, who never (with a straight face) give obscure fractions in game commentaries - they will always say, like Genan, a move is worth "about" X points and, again like him, may occasionally mention half points.

But after Genan we had to wait 80 years before boundary plays were properly treated again in print. This is despite the minor explosion in go journalism in the late 19th century. Instead we had fusekis, josekis, tesujis - but no yose. Again, this almost certainly tells us something about what pros such as Honinbo Shuho thought about priorities.

In the late 1920s, the likes of Kato Shin and Kubomatsu Katsukiyo (who did not use ghost writers) started presenting series on boundary play counting in Kido. The articles were not as well structured as they would be nowadays by a professional go journalist, but essentially they were just presenting what Genan knew.

And by and large that has been the same situation ever since. Periodically, articles of the type Kato and Kubomatsu wrote have been recycled, and have occasionally made it into books. Sometimes you get a whole book on boundary plays, but when you examine it you see that it may be ten pages of "theory" and 230 pages of problems. The only real difference is that the more modern books are apparently written by amateurs. We can say this, not with complete certainty, admittedly, because we see characters and allusions in the text of a level that requires education at an elite university supposedly written by a pro who left school early to devote himself to go. And after the war, we see magazine articles about esoteric technical details of the endgame but these are always by amateurs. For example, Sakaguchi Junei (a very strong amateur) introduced the concept of miai counting to Kido readers in 1955. We also see amateurs' articles about fractional followers and corridors and the like. There had been a minor tradition of amateurs writing about the mathematics of go even before the war, but in the main these were related to the rules of go.

Robert has claimed pros have kept their secrets hidden - the bounders! I think rather that this simply confirms the picture of boundary plays as something that pros did not fuss about very much. They were apparently content with the simplistic model used by Genan and we can infer that they thought we amateurs should be content with it, too. After all, there is a strongly practical reason for thinking that way. Boundary plays tend to come at the end of the game, when time is short. Even pros find it hard to calculate multiple positions using fractions in one-minute byoyomi (and byoyomi can be much shorter!), so they rely on "tricks" such as "that obviously cancels this out so skip the calculation" and they accept the theoretical but highly remote possibility that they may lose a game because they don't quite know how to finesse the fractions. This is exactly how many chess players treat the endgame, too. Quite a lot of pros don't know how to play the K+B+N vs K endgame and so have, on rare occasions, ended up with an embarrassing draw instead of a win. But they have correctly reasoned that they may never see such an endgame in their entire lives.

In fact, in many endeavours, a characteristic of the pro is that they are eminently practical and a characteristic of the amateur is to fuss about trivial details.

Then O Meien came along. He introduced to Japan a new way of treating boundary plays called absolute counting. He said he was surprised Japanese players did not use this superior technique, but it was normal in China (I think he meant what we would call Taiwan). Apart from the novel method, his book was remarkable in that he clearly wrote it himself. Another important feature is that his method, once understood, is very easy to apply. In actual play O Meien does not fuss about sixteenths, corridors or other esoterica any more than his Japanese colleagues do. It's just that his method (or perhaps better: approach) cuts through the confusion caused by de-iri and miai counting (caused by overzealous amateurs?) and also overcomes the delusions that Bill mentions often, such as sente being worth something.

Now Robert says this about O Meien's book:

Quote:
You only understand this good book if you read Japanese or already know all the theory explained in this book. It teaches the very basics of modern endgame theory for local endgames and the most basic global decisions. Endgame 2 - Values teaches more, more details and also the microendgame, scoring and school mathematics but avoids global decisions before the microendgame because they will be the topic of Volume 5. O Meien's book is well worth reading but non-essential if you read Endgame 2 - Values. On the other hand, modern endgame theory has been neglected in the other literature so reading both books can further improve one's understanding.

I have quite a few problems with this. Despite the implication, Robert does not read Japanese. I do read the Japanese, and actually have translated the book. I did this to practise my shorthand (getting very rusty in retirement) and as a way of forcing myself to think about the book. I normally just speed read go books.

So, if Robert cannot read the book, how does he know he already knows all the theory explained in it? His further comments suggest to me he doesn't. For example, the book does not teach much about the very basics of modern endgame theory, because the whole point of the book is to stand up against modern theory as exemplified by what Japanese players use. He barely touches on the very basics such as how to count de-iri style because the basic tenet of his book is about changing attitudes. On top of all that, the climax of the book is the use of a formula for making not "basic global decisions" but rather advanced global decisions to do with winning the game. I see no sign in Robert's self-review that much of what O says appears in "Values", so to say "Values" makes O's book non-essential is, well valueless.

My own view of O's book can be inferred from the fact that I bothered to translate it (nb for myself - don't ask). But I'll be explicit. It can be a slightly irritating book because O is not a born technical writer, but it is not just "good" but excellent. It is the best yose book for amateurs available (by a long way) because the method works. It retains the simplicity and sensible prioritising of previous Japanese books (amateur ghost writers' pages on sixteenths excepted), so it is easy to learn. It is sufficient in itself. OK, it is in Japanese, so you may have to make do with inferior English works, much of the content of which is made redundant by O's insights. But that's hardly O's fault.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #24 Posted: Tue Aug 28, 2018 11:46 am
 Dies with sente

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Bill Spight wrote:
Here is a simple example. Suppose that such a player accurately counts the game and finds that White is 3.5 points behind. He also sees that there are only a few gote left on the board, the largest of which is worth 5 pts. (by deiri counting, which he thinks is the only kind). He erroneously thinks that White, who has the move, has a chance of winning.

Of corse thats true, but you have simply created an example, where miai-counting is more easy/comfortable to use.
It comes to the value of sente:
When the highest play is 5 points gote, then the player with sente can add in average 1.25 points to his score (it could be anything between 0 pints and 2.5).
This shouldn't be confused with the difference between sente and gote, because to pass in this situation will lose 0 to 5 points (in average 2.5 points).

Quote:
Here is another example from real life. I don't remember the exact details, but a 5 dan who was also a computer scientist proposed something like this. Suppose that we have a 4 pt. sente with a simple threat worth 10 pts. (all by deiri counting). We multiply the sente value by 2 to get a value of 8 pts. Then we add the values together to get 18 pts. Then, since there are three plays involved, we calculate the gain for each play by dividing by 3, so the sente play gains 6 pts.

Then there are people who think that because you multiply the value of a sente play by 2, you should multiply the value of a double sente play by 4.

The problem is people who think that they understand deiri counting, who don't.

I think the mistakes in the two last examples result from a bad logic and are not very much related to deiri vs miai.

Let me give an simple example myself.
suppose there are three plays left: A = 4 points gote, B = 5 points gote, C = 3 points reverse sente. The miai-values are A = 2, B = 2.5, C = 3.
Where do you play?
1) If I start with B, then the opponent will play C in sente and take also A.
2) If I start with C, then the opponent will play B and I take A.

Deiri-values:
1) 5
2) 3 + 4 = 7

Miai-valus:
1) 2.5 - 2 = 0.5
2) 3 - 2.5 + 2 = 2.5

Both way show you, that 2) is two points better than 1). I think calculating with deiri-values is here much more comfortable, because you only add what you get.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #25 Posted: Tue Aug 28, 2018 12:15 pm
 Honinbo

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asura wrote:
Bill Spight wrote:
Here is a simple example. Suppose that such a player accurately counts the game and finds that White is 3.5 points behind. He also sees that there are only a few gote left on the board, the largest of which is worth 5 pts. (by deiri counting, which he thinks is the only kind). He erroneously thinks that White, who has the move, has a chance of winning.

Of corse thats true, but you have simply created an example, where miai-counting is more easy/comfortable to use.

Actually, that was based upon an online discussion I chanced upon several years ago. Nobody in the discussion knew anything but deiri values (not by that name, OC). They were doing the best they could with what they had been taught.

Quote:
Quote:
Here is another example from real life. I don't remember the exact details, but a 5 dan who was also a computer scientist proposed something like this. Suppose that we have a 4 pt. sente with a simple threat worth 10 pts. (all by deiri counting). We multiply the sente value by 2 to get a value of 8 pts. Then we add the values together to get 18 pts. Then, since there are three plays involved, we calculate the gain for each play by dividing by 3, so the sente play gains 6 pts.

Then there are people who think that because you multiply the value of a sente play by 2, you should multiply the value of a double sente play by 4.

The problem is people who think that they understand deiri counting, who don't.

I think the mistakes in the two last examples result from a bad logic and are not very much related to deiri vs miai.

They are very much related to how go move evaluation is traditionally taught.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #26 Posted: Tue Aug 28, 2018 1:04 pm
 Honinbo

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asura wrote:
Let me give an simple example myself.
suppose there are three plays left: A = 4 points gote, B = 5 points gote, C = 3 points reverse sente. The miai-values are A = 2, B = 2.5, C = 3.
Where do you play?
1) If I start with B, then the opponent will play C in sente and take also A.
2) If I start with C, then the opponent will play B and I take A.

Deiri-values:
1) 5
2) 3 + 4 = 7

Miai-valus:
1) 2.5 - 2 = 0.5
2) 3 - 2.5 + 2 = 2.5

Both way show you, that 2) is two points better than 1). I think calculating with deiri-values is here much more comfortable, because you only add what you get.

Well, that is not how deiri values are taught or understood by most players. C'est domage, but there you are.

Many players will think that the calculation by deiri values would look like this.

1) 5 - 2*3 - 4 = 5 - 6 - 4 = -5

(Why subtract 3 pts.? Because they do not know that sente does not gain points. Even dan players will argue with you about that. Why multiply the sente value by 2? Because that's what you do to get the deiri value of sente. Why subtract at all? Because they think that deiri values mean the same thing as miai values.)

2) 2*3 - 5 + 4 = 6 - 5 + 4 = 5

{shrug}

----

Edit: Let us represent the plays using CGT notation, with the first player being Black:

A = {4 | 0} + C1 ; C1 being some constant, which we can ignore in the comparison

B = {5 | 0} + C2 ; Ditto C2

C = {3 || 0 | -Big} + C3 ; Ditto C3. Big is a large positive value

Your calculations are fine. But they are not deiri calculations. The players are right that the deiri value of C is 6. They are wrong to apply it to both sente and reverse sente, but nobody taught them that.

What you are using are final results, or final results minus a constant.

1) 5 + C1 + C2 + C3
2) 3 + 4 + C1 + C2 + C3 = 7 + C1 + C2 + C3

You are using final results correctly, but they are not deiri values.

Edit 2: Let's adjust the constants so that the mean value of each position is 0. Just for fun.

A = {2 | -2} + C1 ; C1 being some constant, which we can ignore in the comparison

B = {2.5 | -2.5} + C2 ; Ditto C2

C = {3 || 0 | -Big} + C3 ; Ditto C3. Big is a large positive value

Then we get this.

1) 2.5 - 2 + C1 + C2 + C3 = 0.5 + C1 + C2 + C3
2) 3 - 2.5 + 2 + C1 + C2 + C3 = 2.5 + C1 + C2 + C3

Voila! Using final results for comparison is equivalent to using miai values.

OC, that was your point. This was for the benefit of our readers.

Edit 3: Comparison in terms of final values is always correct. It requires neither miai values nor deiri values.

But miai values, as taught, will yield comparisons that are consistent with final values. Deiri values, as taught, may or may not do so.

Edit 4: I was a bit disappointed to see that Robert included a section on traditional theory in his book. Because the traditional theory has been so poorly taught and understood, whatever he said, he was bound to get an argument. O Meien does not bother with it, and neither would I. (Not that I would not appeal to final values, since doing so is always correct. In fact, I would start by appealing to final values.)

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Last edited by Bill Spight on Tue Aug 28, 2018 2:58 pm, edited 9 times in total.
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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #27 Posted: Tue Aug 28, 2018 1:06 pm
 Tengen

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John, I need not read Japanese to understand most of the calculatios in O's book because they are clear from the written arithmetics, move / diagram references, words whose meaning is apparent from text-positional context, recognising a few kanjis, knowing modern endgsme theory and therefore knowing what kinds of values might be being calculated, your earlier explanation of error margins and a few answers by others here on my most relevant missing aspects of understanding the contents.

In recent years, some Asian professionals at European Go Congresses showed their interest in fractional endgame values, expecting us to calculate them precisely. History changes and imprecision of the past is overcome by those professionals taking evaluation seriously.

You are trying to make fun of the 16th fraction. There are times when rounding is good enough and times when accurate fractions are needed to order moves of similar values or other purposes. Do not pretend that similar move values would not occur. Such decisions are frequent. With iterative follow-ups, higher fractions occur. Distinguishing them decides close games.

Massive overkill? Do you deny that the following is useful and important? Evaluating positions, evaluating moves when Black's and White's moves gain different amounts, evaluating how much more a player gains during a sequence, playing moves in their correct order during the early endgame, as before during the late endgame (before the microendgame) etc. Nothing of this is an overkill. Quite contrarily, each such aspect is of central importance. Even Ben Lockard is aware of appreciating different values of next Black and White moves, as he reports after coming back from studying in Korea, see the Surrounding Game.

Wake up. Ignorance of useful endgame concepts is the past. Excessive rounding is for beginners or lazy, advanced players. Improving means better appreciating the details. Says not only Kageyama. Every professional at EGCs stresses this attitude, even the Japanese.

Last edited by RobertJasiek on Tue Aug 28, 2018 9:40 pm, edited 1 time in total.
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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #28 Posted: Tue Aug 28, 2018 2:42 pm
 Honinbo

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John Fairbairn wrote:
We know that de-iri counting was known before 1844, because that was when Genan published what he claimed was the first book on counting boundary plays. He did not use the term de-iri, which may not have been used until the early 20th century, and he did not claim to have invented the concept (despite being brash enough to publicise himself) and he did not feel the need to explain the counting method. All this strongly suggests the method was already well known then, and since the endgame play of Edo players is regularly praised even today we may safely assume it already had a long history. That is, there had already been ample time for refinements to emerge.

The method may well have originated in the Inoue house. I suspect that publication indicates that players in other houses had caught on by then. Perhaps secrets had been leaked.

Quote:
Sakaguchi Junei (a very strong amateur) introduced the concept of miai counting to Kido readers in 1955. We also see amateurs' articles about fractional followers and corridors and the like.

{snip}

Then O Meien came along. He introduced to Japan a new way of treating boundary plays called absolute counting. He said he was surprised Japanese players did not use this superior technique, but it was normal in China (I think he meant what we would call Taiwan). Apart from the novel method, his book was remarkable in that he clearly wrote it himself. Another important feature is that his method, once understood, is very easy to apply. In actual play O Meien does not fuss about sixteenths, corridors or other esoterica any more than his Japanese colleagues do. It's just that his method (or perhaps better: approach) cuts through the confusion caused by de-iri and miai counting (caused by overzealous amateurs?) and also overcomes the delusions that Bill mentions often, such as sente being worth something.

{snip}

My own view of O's book can be inferred from the fact that I bothered to translate it (nb for myself - don't ask). But I'll be explicit. It can be a slightly irritating book because O is not a born technical writer, but it is not just "good" but excellent. It is the best yose book for amateurs available (by a long way) because the method works. It retains the simplicity and sensible prioritising of previous Japanese books (amateur ghost writers' pages on sixteenths excepted), so it is easy to learn. It is sufficient in itself. OK, it is in Japanese, so you may have to make do with inferior English works, much of the content of which is made redundant by O's insights. But that's hardly O's fault.

JF believes that O Meien's method is new despite being miai counting, because of the very poor way that miai counting was treated in prior literature. (Although Takagawa treats it properly in his Igo Reader series, as I recall.) No wonder John did not recognize it. O's book deserves the high praise that John gives it.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #29 Posted: Tue Aug 28, 2018 6:06 pm
 Dies with sente

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Bill Spight wrote:
asura wrote:
Let me give an simple example myself.
suppose there are three plays left: A = 4 points gote, B = 5 points gote, C = 3 points reverse sente. The miai-values are A = 2, B = 2.5, C = 3.
Where do you play?
1) If I start with B, then the opponent will play C in sente and take also A.
2) If I start with C, then the opponent will play B and I take A.

Deiri-values:
1) 5
2) 3 + 4 = 7

Miai-valus:
1) 2.5 - 2 = 0.5
2) 3 - 2.5 + 2 = 2.5

Both way show you, that 2) is two points better than 1). I think calculating with deiri-values is here much more comfortable, because you only add what you get.

Edit: Let us represent the plays using CGT notation, with the first player being Black:

A = {4 | 0} + C1 ; C1 being some constant, which we can ignore in the comparison

B = {5 | 0} + C2 ; Ditto C2

C = {3 || 0 | -Big} + C3 ; Ditto C3. Big is a large positive value

Your calculations are fine. But they are not deiri calculations.

What you are using are final results, or final results minus a constant.

1) 5 + C1 + C2 + C3
2) 3 + 4 + C1 + C2 + C3 = 7 + C1 + C2 + C3

You are using final results correctly, but they are not deiri values.

However, exactly this is the method, that Ogawa use! I have always thought, this mehod would be called deiri and I think Robert also said this book uses deiri.
Anyway, in the book, you multiply reverse sente with two ONLY to compare it to a gote. For me this exactly equivalent to dividing the gote by two.
It would make no sense, to double a sente or reverse sente on the bord, because if I make two points in sente by capturing one stone, how should it ever become four points?

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #30 Posted: Wed Aug 29, 2018 1:35 am
 Gosei

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Even as a mathematician, I'm with John F. on this one. For all practical purposes, on amateur level, "fractions gain nothing". That is not to say that the theory should not be developed and neither will I argue that professionals can benefit or not from better theory. Pros are squeezing out the last half point and when dealing with AIs who calculate winning probabilities, pros probably need very sharp (endgame) theory. No progress was ever made by mocking new development." However ...

Amateurs need to make less mistakes. And we make plenty, regardless of whether we understand deiri/miai counting.

If you take the example of (A=4 gote, B=5 gote, C is 3 sente for White) and this is all that remains on the board then Black should indeed take C first. You don't have to know any counting method for that, you just perform basic arithmetic in a short logic tree.

Such examples rarely occur in reality, where a high number of plays is available and you need a good, practicle heuristic for any situation under time pressure. That heuristic is:

"Take your big sente first (small sente serve as ko threats)
then take the largest gote"

Yes, we will make a mistake in the above situation, ignoring the reverse sente. But on average, we'll make less mistakes, because in reality there will not be a construction of two remaining gote, but a gote sequence A1, A2, ... with some sente mixed in between which become big enough to waste as a ko threat.

Then there is the matter of who is ahread. Here the heuristic is:

"If you are ahead, be conservative, respond to sente; make no exchanges and avoid major kos
if you are behind, take more risks, revoke sente, apply mutual damage and seek ko"

Now, what I'm writing here can be wrong or an exaggerated simplification even for amateurs, but this is the kind of thing amateurs should think about. Discussing counting methods and fractions is very interesting in itself, but does it really lead to manageable decision making which is significantly more correct under time pressure? What are your experiences, as players, Bill, Robert ...

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #31 Posted: Wed Aug 29, 2018 2:40 am
 Tengen

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As a player, my endgame has improved a lot from considering fractions whenever necessary. Previously, Hayashi Kozo (the currently most popular professional visiting EGCs) noticed my strong positional judgement during the middle game but now he is more impressed by my endgame, praising it regularly.

I also like efficient time management and use simpler evaluations or comparisons when applicable correctly. My calculation speed is still somewhat slow for iterative follow-ups but what used to be 10 - 20 minutes per difficult local endgame a couple of years ago has become more like 15 seconds to 4 minutes. This acceleration is mostly the effect of understanding the theory well now. Surely, I need much more practice to further accelerate such calculations.

Also the microendgame helps. It makes a great difference having no idea at all versus understanding its basics. Fractions hardly need to be calculated for the microendgame because there are simpler principles. Nevertheless, understanding what the fractions or integers are in principle assists the overall understanding of the microendgame.

Playing under area scoring without knowing any of its endgame theory lets one feel hopelessly lost and spend 10 minutes on counting stones and whatnot. The theory is simple but rediscovering it during one's game is close to impossible.

Ko evaluation has become much easier. Now I profit from my opponent's mistakes if they have neglected study of the theory.

The occasional tesuji helps, especially if the opponent overlooks it. Reading blunders of overlooking simple variations may be my greatest endgame weakness at the moment.

Especially weaker opponents make (even big) mistakes in endgame evaluation when relying too much on guessing relative sizes of move values instead of calculating them at least accurately enough for comparing them numerically to close alternative candidates.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #32 Posted: Wed Aug 29, 2018 3:06 am
 Honinbo

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As a practical matter, my attitude towards 16ths is pretty much the same as my attitude towards winrate differences of less than 1%: Don't strain after gnats. However, that attitude does not extend to 8ths, based upon traditional yose literature, where it is usual to talk of values of plays as 4 pts. plus or 6½ pts. minus. OC, these are deiri values. To translate to miai values we divide by 2, so 6½ pts. minus becomes 3¼ pts. minus. 3¼ pts. minus covers the range between 3¼ and 3; IOW, 3⅛ more or less. To get to 8ths only requires reading and calculating to depth 3, after all. That is practical.

That said, if the game is very close, where a difference of 1 pt. matters, an error of 1/16 pt. is on the order of a winrate error of 6.25%, which we regard as serious. (It matters by area scoring, as well. Remember that a 1 pt. error by territory scoring can become a 2 pt. error by area scoring.)

Well, it's my bedtime. More later.

_________________
At some point, doesn't thinking have to go on?

Last edited by Bill Spight on Wed Aug 29, 2018 10:15 am, edited 1 time in total.
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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #33 Posted: Wed Aug 29, 2018 4:16 am
 Oza

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I think the wrong question is being answered. The real question is implicit in what knotwilg wrote, and even in how Robert answered. If you have limited study time (as all amateurs and even many pros do) is it better to spend it on, say, endgame tesujis or learning to calculate sixteenths at high speed? Robert says: "Reading blunders of overlooking simple variations may be my greatest endgame weakness at the moment." I rest my case, m'lud.

Actually, I don't. I think even more fundamental to all this is personality type. Within sensible limits, no one type is better than another, of course, and I'm sure only the sensible types are represented here.

There is another example of Robert's type I'm familiar with in linguistics. Gaelic pronunciation is notoriously difficult. People write jokey books about it, but most people run away in fright. My father was fond of Gaelic and I was a linguist, but I too was one of those who ran away. As an example, not at all exaggerated, of the difficulties, take the common word piobaireachd. In its Scots/English form of pibroch the word is familiar to more than a few English speakers, even in the US, as "something to do with bagpipes" even if they don't quite know what it means (it's a way of playing variations on a theme, usually a funerary or martial theme, and it's therefore a big component in bagpipe competitions). See, you haven't wasted time reading this - you've learnt something new and important!

Now there's a scholar who has written a very large book of nearly 600 pages that is designed to tell you how to pronounce (Scots) Gaelic. It doesn't teach anything else - no grammar, no vocabulary. Many Gaelic speakers claim that the Gaelic spelling system is a divine and beautiful creation, ignoring the fact that the system has been changed quite regularly and recently, which means that using a dictionary more than a few weeks old can be rather fraught. Our scholar is not quite so impressed by the hand of God but does believe that the system is beautiful because it is logical and consistent, and you can turn the rules into a list. You can see the analogy with our go scene, I'm sure.

The scholar's work is actually very impressive (and the book is rather well written). But if you want to know how to pronounce the letter e, for example, you have to work your way through a list of 29 rules. To take just the first rather simple rule, you have to establish whether it is accented and whether it is followed by m, mh or p. And once you've done that the rule tells you only that it is usually pronounced in a certain way. Some other rules can take almost a whole page to work through. Each letter has many such rules and the total number of rules is of the order of 450, and the list alone takes over 100 pages. Our scholar obviously enjoyed compiling it.

This is the Gaelic equivalent of sixteenths. But guess what. It's easy to find words that aren't covered by the rules, and kids speaking Gaelic on the Isle of Skye manage perfectly well without this book, as in the past have great poets such as Sorley Maclean (or as he would have written it: Somhairle MacGill-Eain).

Again, I think you can see the analogy with go.

So it's not just a question of how you best allocate your time. It's also a question of what you enjoy doing. But my experience is that most people would prefer to improve by 10 points rather than by a sixteenth of a point.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #34 Posted: Wed Aug 29, 2018 4:39 am
 Lives in gote

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I will read Robert's new book because I am interested in a better understanding of the theory, even if my level doesn't improve.

My goal is not to become a champion, or to spend all my free time working hard in order to gain a few kyus. My goal is to enjoy a game that I like. And I would like to learn about endgame theory, just for fun, if not to improve. I won't crush my opponent using this knowledge, but it will turn the endgame part more enjoyable.

I am currently 5 kyu KGS / 9 kyu french rating. Regarding endgame theory, I have read Learn to Play go until volume 5 (Janice Kim), Yose (Dai Junfu), and First Fundamentals (Robert Jasiek).

For the time being, the only counting method that I am aware of is counting the difference between the position after black to play and the position after white to play. But it is awfully confusing in area scoring because the values are affected by the number of black and white stones played. It even seems to completely loose its meaning when there are follow-ups, the area values diverging completely from the territory values. I have more or less admitted that anyway, territory counting does the job all right, since in most situations, the outcome is nearly the same under both rules.

I have always learned to prioritize double sente, then sente, then reverse sente, then gote, but I could never remember which one is worth the double of which one. I just know that something doubles somewhere.

Playing double sente before sente, and reverse sente before double gote seems natural to me : if sente is better than gote, then removing sente moves from my opponent's possibilities is good for me.

I've learned in my club, from a dan player commenting one of my games, that I didn't have to sheepishly follow the sente moves of my opponent : it is always possible to answer a sente move with another sente move elsewhere.
This illuminating moment opened the world of mutual reduction and the relativity of "sente" to me. Obviously, if I answer a sente move with another sente, my opponent has the choice between answering my sente (And I get half of the endgame sequences instead of leaving everything to the opponent), or starting the mutual reduction, and I'd better have chosen a more dangerous sente than him, or the mutual reduction will be at my disadvantage !

Using the little I know about endgame theory, I came to the conclusion that I should play a 2 points gote endgame before pushing into a corridor, because in the latter case the value should be something like 1 + 1/2 + 1/4 etc gote, which is less than 2. But since the values are so close, any other consideration, such as safety of the overall group, or psychological pressure (luring my opponent into believing that the move is sente) etc, takes precedence.

I have always been confused by the values of kos. I came to the conclusion that the last ko (if it has no follow up) has an absolute value of two intersections changing colours in area scoring (french rules), rather than 1/3rd of a point, although I admit (without understanding the demonstration) that 1/3 of a point is the right endgame count to use in order to prioritize it among other possible endgame moves. So I always fight the last ko after everything else and before filling the dame.
However, I am completely unable to know the value of a pair of two kos one opening the other, and with no other follow up after the second ko is connected. I don't know if I have to try to win this before a 2 points gote endgame.
Although this is not something important in my games, I feel very frustrated by my complete inability to understand such a basic position. That's why I am interested in microendgame. Not to win tournaments, but to understand what I am doing.

Last edited by Pio2001 on Wed Aug 29, 2018 4:46 am, edited 1 time in total.
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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #35 Posted: Wed Aug 29, 2018 4:45 am
 Tengen

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As I have always said, avoiding blunders is the first priority. This does not mean one should not study anything else just because one makes blunders. We also know that improvement fails if one neglects a study field too much. Neglecting endgame evaluation entirely is no option at all.

Learning tesujis is a fast way for improving a rank or two as 12 - 8 kyu. As is learning to stop the monkey jump at all.

Most endgame decisions can be guesswork because it is fairly easily to distinguish moves of significantly different sizes. This still leaves, say, 40% of the endgame value decisions to be done by calculation. Almost all endgame moves depend on size rather than tesuji or reading. That is, avoiding calculation entirely is plainly wrong for SDK / dan players.

When learning, it is possible to calculate +-3, then +-2, +-1, +-1/2, +-1/4, +-1/8, and eventually accurate whenever possible. If you calculate +-1/2 during your, say, 75 endgame moves and round wrongly half of the time, your mistakes amount to 75 * 1/2 * 1/2 ~= 19 points, or 1.5 ranks. That is why I do not recommend sticking to rounding for too long. (More) accurate calculations have just a too great impact because there are too many endgame moves and moves with endgame aspect earlier during the game.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #36 Posted: Wed Aug 29, 2018 7:38 am
 Gosei

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RobertJasiek wrote:
As I have always said, avoiding blunders is the first priority. This does not mean one should not study anything else just because one makes blunders. We also know that improvement fails if one neglects a study field too much. Neglecting endgame evaluation entirely is no option at all.

Learning tesujis is a fast way for improving a rank or two as 12 - 8 kyu. As is learning to stop the monkey jump at all.

Most endgame decisions can be guesswork because it is fairly easily to distinguish moves of significantly different sizes. This still leaves, say, 40% of the endgame value decisions to be done by calculation. Almost all endgame moves depend on size rather than tesuji or reading. That is, avoiding calculation entirely is plainly wrong for SDK / dan players.

When learning, it is possible to calculate +-3, then +-2, +-1, +-1/2, +-1/4, +-1/8, and eventually accurate whenever possible. If you calculate +-1/2 during your, say, 75 endgame moves and round wrongly half of the time, your mistakes amount to 75 * 1/2 * 1/2 ~= 19 points, or 1.5 ranks. That is why I do not recommend sticking to rounding for too long. (More) accurate calculations have just a too great impact because there are too many endgame moves and moves with endgame aspect earlier during the game.

While I believe it is not impossible to reach expert level in the endgame by taking the route of fractions, I believe John's comparison to the book of 600 pages on Gaelic pronunciation is spot on. There is another way, the way chosen by native speakers and professional go players. As amateurs moving into the matter in adult life, it is almost impossible to catch up with native speakers or go professionals who learnt go at an early age. So it may be that the book of Gaelic pronunciation or fractions are the better way for amateur latecomers. My bet is on emulating the native/professional way, even if we keep falling short. Probably I find that more enjoyable too, but clearly others enjoy different ways.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #37 Posted: Wed Aug 29, 2018 8:16 am
 Tengen

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As interesting as Gaelic may be in itself, how can a dynamic pronunciation be a good metaphor for a static endgame (regardless whether we consider the game tree of go or of a particular go game position)?

You mention the way chosen by professional go players, uhm, but aren't they different? What are their ways aka degrees of accuracy during the endgame? For decades, I have heard praise of professionals attempting to fight for the last point, by myth perfect endgame during the Edo period and admiration of exceptional skill such as Ishida Yoshio, the "computer". I have mentioned more evidence.

Just to repeat the obvious: there is nothing wrong with approximations IF WE KNOW THAT THEY STILL PRODUCE CORRECT RESULTS. Are there any professionals that play flawed endgame deliberately? I do not think so. When approximations are not good enough to determine correct play, we do need accurate (or almost accurate approximative) calculations.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #38 Posted: Wed Aug 29, 2018 8:21 am
 Judan

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BTW, when Mateusz Surma (now 1p EGF) was studying in a Go school in China he did problems with yose calculations down to 1/48 of a point: http://mateuszsurma.pl/en/2016/04/15/sc ... 5-04-2016/ I think it quite likely Japanese pros of the 1970s study in a different way to kids aspiring to be pros in a go school in China in the 2010s.

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #39 Posted: Wed Aug 29, 2018 8:28 am
 Tengen

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His follow-up report is here http://mateuszsurma.pl/en/2016/05/

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 Post subject: Re: Review: The Endgame (Ogawa / Davies) #40 Posted: Wed Aug 29, 2018 8:40 am
 Gosei

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Uberdude wrote:
BTW, when Mateusz Surma (now 1p EGF) was studying in a Go school in China he did problems with yose calculations down to 1/48 of a point: http://mateuszsurma.pl/en/2016/04/15/sc ... 5-04-2016/ I think it quite likely Japanese pros of the 1970s study in a different way to kids aspiring to be pros in a go school in China in the 2010s.

OK. So pros know about fractions and use them to calculate positions in problems. The question is: do they use them nowadays in their decision making? Do they effectively, in the late endgame, rank moves according to these calculated values? Given five or more moves to evaluate, I would think they need to know these values by heart. Nothing is impossible, in a mankind where already three centuries ago professional composers could make a composition for an orchestra without ever hearing it elsewhere than in their head. But do they? Or will they calculate these >5 moves on the fly? Or will they intuitively prune it down and choose the one with the highest winning probability, including the effect on neighboring positions and potential ko?

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