How to learn to count during midgame

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Re: How to learn to count during midgame

Post by snorri »

RobertJasiek wrote:

snorri wrote:and you are only disclosing the difference in the number of prisoners.


Exactly. This has advantages: 1) One needs to keep in mind only one instead of two numbers. 2) The number can be smaller in many cases; the overhead of further prisoners of both players need not be carried along. 3) The difference of prisoners is already calculated; one need not do that in future.


It might help if you stated that motivation up front. I hope your book does so. But I'll acknowledge that you can't reproduce your book here.

RobertJasiek wrote:Because numbers and signs don't bite back and warn the player using them! If he does make such mistakes, then he needs to become aware of them by himself. He must understand whether his calculations are done correctly. Chances are that he does not necessarily notice if is already making the mistakes. It is better if he develops the related understanding before starting calculations.


I don't understand. Your "correct" approach avoids neither numbers nor signs. Certainly avoiding numbers is not possible! Signs didn't come up in the example, but what if the initial position assumed there more 100 more black prisoners than white? Wouldn't you use a negative number there?


RobertJasiek wrote:It is good to see that you have enough understanding to find your own mistakes! Was your understanding also good enough to describe prisoner handling during the previous weeks, while I waited to see if somebody could describe it? Now, that I have offered some description, suddenly everybody comes and proclaims how simple and obvious everything is. I said so weeks ago:)


I can't speak for other people. As for myself, I didn't understand what you had in mind regarding prisoner handling. Now it is clear that you are referring to possible problems players might have with mental bookkeeping.

RobertJasiek wrote:No. The difficulty arises also if you keep track of two different prisoner numbers (#black stones and #white stones) for every purpose. E.g., alternatively you could mentally store two numbers for the initial prisoner difference, two numbers for the prisoners removed during the imagined sequence for determining black territory, two numbers for ... sequence for... white territory. (I prefer 3 instead of 6 numbers for prisoners.)


I'd think that's a different problem.

RobertJasiek wrote:Suppose you are determining a particular player's territory. Why dubious? Are you suggesting to ignore all prisoners? Sure?;) Of course, you must consider prisoners! So, please, specify your preferred method for this case of application!


I'm not suggesting ignoring prisoners. I would use your "correct" method which applies the prisoner difference afterward only when calculating the total count. I dare say you did state the obvious there.

RobertJasiek wrote:Imagine any example of territory with dead stones in atari and near the boundary of a region. When the opponent reduces that region, you create prisoners.

Proceed to a more complicated kind of examples: teire with throw-ins. You will see that simply keeping dead stones on the board would be an insufficient model in general for assessing a region's territory value.


I think you should have started with that example, as I don't think the first one presents too many difficulties. But if you've seen those difficulties with your students, I suppose they are possible. I tend to classify that sort of thing on the same order of concentration problem as forgetting to account for komi, but I'm willing to consider the possibility that it's a different class of blunder.

Let's start with the boundary problem where dead stones are removed during the mental process of reading out variations to get to some kind of quiet, countable position. Before we go further, is this the kind of position where the kinds of mistakes you are referring to with respect to prisoner counting are more likely to occur? If not, feel free to modify or replace with your own example. I'm sorry of this one appears too endgame-like, but I'm afraid that with true middle-game ones one can argue too much about what the proper reduction sequences are rather than the counting itself. (That's the hardest part of counting for me, other that just speed.)

Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O . . . . . O X O X . . . . . X . . |
$$ | . O . O . O . O X O X . X . X . X . . |
$$ | . . . , . . . O X O X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


Edit: made slight mod to diagram.
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Re: How to learn to count during midgame

Post by snorri »

RobertJasiek wrote:
topazg wrote:you're pretty badly misinterpreting (and rephrasing) what he's saying.


Ok, let me cite of what he says:

"you must factor thickness, weakness, aji, etc."

This is nebulous because he does not say at all HOW to do so.

"they look at each position by deciding who has more rights to the position"

This is nebulous because he does not say at all HOW to determine who has more rights.


These discussions can be tiresome but also entertaining. In this case, I do feel MagicWand oversimplifies, although not to the extent of his post where he says it is important to learn how not to lose. I eagerly await his book on that topic. :)

I think both views have some validity. MagicWand seems to be of the school that one doesn't have to know much to get stronger, that it's mostly experience. (He's even been so bold as to deny the existence of bad habits in go, which I think is an unorthodox view.) So I think that he accepts that a lot of examples/experience are required to get good.

Robert seems to be on a crusade to show that there's a better way than just examples, and it's clearly very personal to him. It's an ambitious agenda. I disclose that I have Robert's 3 Joseki books and I have trouble with them. He may indeed have a mental model that structures his heuristics in his own brain that works for him, but I'm not sure transplanting that will work. Some things you do have to reconstruct for yourself to understand.
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Re: How to learn to count during midgame

Post by RobertJasiek »

snorri wrote:It might help if you stated that motivation up front.


It might be in the introduction, which I still need to write. An even greater motivation is: When doing positional judgement (PJ) in my games, I keep track of (only) the initial prisoner difference instead of the numbers of black / white prisoner stones. Don't you, too? It is easier having to remember only one such number!

Your "correct" approach avoids neither numbers nor signs. Certainly avoiding numbers is not possible!


Ah, no, that is not what I am trying to say:) Rather:

Calculations are needed for reasonably accurate PJ. They include numbers and signs. (Yes, also + or - signs.) To get good PJ, the calculations must be correct. However, when one makes them, one can also make calculation mistakes. What you write or mentally write as a calculation does not yell at you when you make a mistake. You need to notice by yourself when you do.

Signs didn't come up in the example,


They did. (Maybe if I speak of arithmetic operations and write +8 instead of 8, you notice more easily.)

but what if the initial position assumed there more 100 more black prisoners than white? Wouldn't you use a negative number there?


Sure.

you are referring to possible problems players might have with mental bookkeeping.


This is one of the problems, and comes in various forms. (Thanks for suggesting the phrase!) Another problem is understanding when prisoners occur but are not counted twice.

I dare say you did state the obvious there.


Now, it is obvious for me. When I started writing, it was not. Describing things carefully helps:)

Before we go further, is this the kind of position where the kinds of mistakes you are referring to with respect to prisoner counting are more likely to occur?


Yes, this is one possible kind. (A nice variety of endgame contained in the middle:) )
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Re: How to learn to count during midgame

Post by RobertJasiek »

snorri wrote:and I have trouble with them.


If you like, please tell which trouble. (Or by email / PM, if you prefer.) I am always interested in hearing feedback.
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Re: How to learn to count during midgame

Post by Magicwand »

snorri wrote:
Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O . . . . . O X O X . . . . . X . . |
$$ | . O . O . O . O X O X . X . X . X . . |
$$ | . . . , . . . O X O X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]



[quote="snorri"]
Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . B x . . . . . . . . |
$$ | . O . . . . . O X c X . . . . . X . . |
$$ | . O . O . O . O X c X . X . X . X . . |
$$ | . . . , . . . O X c X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


[quote="snorri"]
Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . x W . . . . . . . . . . |
$$ | . O . . . . . O C O X . . . . . X . . |
$$ | . O . O . O . O C O X . X . X . X . . |
$$ | . . . , . . . O C O X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


difference between two diag is 14 points
now add 1/2 points for leftover 1 point gote.
so total is 14 and half point value + alpha (alpha being less than 1 point)
"The more we think we know about
The greater the unknown"

Words by neil peart, music by geddy lee and alex lifeson
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Re: How to learn to count during midgame

Post by RobertJasiek »

Magicwand wrote:for leftover 1 point gote.


In most practical cases, a follow-up would not be gote but it would be reverse sente for the defender or sente (privilege) for the attacker.

Click Here To Show Diagram Code
[go]$$W positional judgement: black territory
$$ ---------------------------------------
$$ | . . . . . . . . 1 . 2 . . . . . . . . |
$$ | . O . . . . . O X O X . . . . . X . . |
$$ | . O . O . O . O X O X . X . X . X . . |
$$ | . . . , . . . O X O X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


Click Here To Show Diagram Code
[go]$$B positional judgement: white territory
$$ ---------------------------------------
$$ | . . . . . . . 2 . 1 . . . . . . . . . |
$$ | . O . . . . . O X O X . . . . . X . . |
$$ | . O . O . O . O X O X . X . X . X . . |
$$ | . . . , . . . O X O X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


When determining Black's territory and, by assumptions of no relevant outside aji and local reduction plays being local sente, letting the defender reply by defending in response to the reducing attacker, then...

so total is 14 and half point value + alpha (alpha being less than 1 point)


...an alpha is not needed here! Considering only this suitable locale...

Click Here To Show Diagram Code
[go]$$B locale
$$ ---------------------------------------
$$ | . . . . . . . C C C C . . . . . . . . |
$$ | . O . . . . . O B W X . . . . . X . . |
$$ | . O . O . O . O B W X . X . X . X . . |
$$ | . . . , . . . O B W X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


...and comparing the counts by calculating the territory count, that is, Black's minus White's territory, (incl. either sequence's prisoner difference) in that locale after either reduction sequence, we get the positional judgement's territory count -7 - (-7) = 0 points. (In the locale, when determining Black's territory, White makes points; when determining White's territory, Black makes points. Therefore we have negative values from either defender's perspective.)

When you calculate a value like 14 points (including sente follow-ups considered as privileges), then that does not express a positional judgement's territory count, but expresses an endgame value: the so called deire value. Expressed as a miai value (per excess plays, here: 2 because either Black plays 1 play more or White plays 1 play more), the endgame value becomes 14/2 = 7.

Also for this calculation referring to privilege follow-ups, an alpha is not needed. However, now I get at least a rough idea of how you suggest usage of an alpha during endgame calculations when suddenly follow-up values drop dramatically. Before your last message, I had guessed that you would suggest a pretty different usage of an alpha: as an assumption by means of a separation line between a moyo's assumed safe territory and its insecure potential territory, for which one would not calculate territory at the moment but include the insecure intersections in the alpha to see which player is alpha behind on the whole board and needs at least alpha on the insecure / open rest of the board to catch up.

EDIT: corrections, in particular: twice replace 6 by -7
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Re: How to learn to count during midgame

Post by RobertJasiek »

In my previous message, I did not consider the endgame values too carefully. Let me do this now. I.e., the following is endgame value calculation - it is not for positional judgement during the middle game.

Click Here To Show Diagram Code
[go]$$B endgame locale
$$ ---------------------------------------
$$ | . . . . . . C C C C C C . . . . . . . |
$$ | . O . . . . . O B W X . . . . . X . . |
$$ | . O . O . O . O B W X . X . X . X . . |
$$ | . . . , . . . O B W X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


For endgame calculation of determining move sizes, this locale is suitable.

Click Here To Show Diagram Code
[go]$$B Black move, 2 = pass
$$ ---------------------------------------
$$ | . . . . . . 4 3 . 1 . . . . . . . . . |
$$ | . O . . . . . O X O X . . . . . X . . |
$$ | . O . O . O . O X O X . X . X . X . . |
$$ | . . . , . . . O X O X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


If Black moves first, then he gets the gote move 1 and its follow-up privilege 3, which White 4 must answer.

Click Here To Show Diagram Code
[go]$$B resulting position, prisoner difference = 3
$$ ---------------------------------------
$$ | . . . . . . O X . X C C . . . . . . . |
$$ | . O . . . . . O X C X . . . . . X . . |
$$ | . O . O . O . O X C X . X . X . X . . |
$$ | . . . , . . . O X C X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


In the locale, Black makes 5 + 3 = 8 points for himself.

However, there is the remaining basic endgame ko, which (under territory scoring) is worth something for White, i.e., it is worth something negative for Black. Using Magicwand's symbol, let us call that alpha. So, to be precise, Black makes (8 - alpha) points.

Click Here To Show Diagram Code
[go]$$W White move, 2 = pass
$$ ---------------------------------------
$$ | . . . . . . . . 1 . 3 4 . . . . . . . |
$$ | . O . . . . . O X O X . . . . . X . . |
$$ | . O . O . O . O X O X . X . X . X . . |
$$ | . . . , . . . O X O X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


If White moves first, then he gets the gote move 1 and its follow-up privilege 3, which Black 4 must answer.

Click Here To Show Diagram Code
[go]$$B resulting position, prisoner difference = -3
$$ ---------------------------------------
$$ | . . . . . . C C O . O X . . . . . . . |
$$ | . O . . . . . O C O X . . . . . X . . |
$$ | . O . O . O . O C O X . X . X . X . . |
$$ | . . . , . . . O C O X . . . . , . . . |
$$ | . . . . . . . O O X X . . . . . . . . |[/go]


In the locale, White makes 5 - (-3) = 8 points for himself. (The sequence's prisoner difference is negative because it is white prisoner stones minus black prisoner stones. Since we are determining White's points from White's perspective and the prisoner difference is expressed from Black's perspective, we must subtract the prisoner difference.)

However, there is the remaining basic endgame ko, which is worth something for Black, i.e., it is worth something negative (to be subtracted) for White, let us call that -alpha. (Negative sign in front of alpha because it is the inverse of the alpha used in the black points calculation.) So, to be precise, White makes (8 - (-alpha)) points.

Now, we have Black's (8 - alpha) points in the locale and White's (8 - (-alpha)) points in the locale. Both players' values together amount to

Deire value = (8 - alpha) + (8 - (-alpha)) = 8 + 8 - alpha + alpha = 8 + 8 = 16 points.

The miai value is 16 / 2 = 8 points.


EDIT: major corrections. I hope, it is correct now.
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