Click Here To Show Diagram Code

[go]$$W White to play
$$ ----------------------------
$$ . . . . . . . b . . . . . |
$$ . . . . . . . . . a O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

I saw this yose problem in a quite old endgame book (1976) and the author claimed the best yose move for white was the gote move at "a".
I am wondering if a move at "b" may be better, hoping for a sente sequence.
What is your view?

Taking b as net score 2 points (4 + -2) [diagram A], I think a would be the middle ("average") between (black responds) net score 2 points (4 + -2) [diagram B] and (black tenuki) net score -5 points (0 + -5) [diagram C] = -1.5 points.
So a is 3.5 points better for white than b.

At least I think this is the endgame calculation method that InSeong Hwang teaches in his online go school (barring privilege / follow-up sequence mistakes that I may have made).

Click Here To Show Diagram Code

[go]$$W A: net score 2 points
$$ ----------------------------
$$ . . . . . T 4 1 3 7 S S . |
$$ . . . . . 0 T 2 6 5 O 9 . |
$$ . . . . . . . X Q 8 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Click Here To Show Diagram Code

[go]$$W B: net score 2 points
$$ ----------------------------
$$ . . . . . T T 6 4 5 S S . |
$$ . . . . . T T 2 3 1 O 9 . |
$$ . . . . . . . X O 8 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Click Here To Show Diagram Code

[go]$$W C: net score -5 points
$$ ----------------------------
$$ . . . . . 6 5 7 S S S S . |
$$ . . . . . 0 4 3 9 1 O S . |
$$ . . . . . . . X O 8 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Edit: fixed an arithmetic error.

Without looking too closely, I feel like if black plays B and white tenukis, black's best follow-up is still A, so B is just a suboptimal gote move.

Taking your diagA I am not sure your move is correct because of the following answer:

Click Here To Show Diagram Code

[go]$$W A
$$ ----------------------------
$$ . . . . . . 3 1 . . . . . |
$$ . . . . . . . 2 . . O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

I think you have to play the move and in the other order:

Click Here To Show Diagram Code

[go]$$W A: net score 2 points
$$ ----------------------------
$$ . . . . . T 2 1 3 7 S S . |
$$ . . . . . 0 T 4 6 5 O 9 . |
$$ . . . . . . . X Q 8 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Let's take your result for diag A and C. I agree here with your count: the white gote sequence allows white to gain 7 suplementary points.
Now the basic question is: in this situation, with a difference of 7 points, do you prefer the sente sequence or the gote one?

Concerning your diag B isn't it better for black to play

Click Here To Show Diagram Code

[go]$$W White to play
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . 2 1 O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

In the position created by the previous move, the average between Black continues or White continues (because Black tenukis) is the count of that position if, at its own moment, it is a local gote.

Therefore, to possibly use this gote count, one must verify whether that position is indeed a local gote. If it is, the use of this gote count for value calculations of the initial position requires justification. With what justification do you want to do so?



Uh, is it, or do you not know, what is the related method he teaches? If eventually you know, what exactly is it for traditional or modern endgame theory?

Oops. Fortunately my move order mistake doesn't change the net score evaluation for diagram A.


I admit that my evaluation of diagram B was a bit hand-wavy. It was more an approximation that I might apply in an actual game with limited time available. A more accurate score calculation would involve more variations and take more time.

To compare black's atari in your diagram with diagram B (i.e. black takes gote), I'll assume black connects if white connects [diagram D]. Without expanding the move tree further, I estimate the net score as about 2 points (5 + -3), which is the same as the net score for diagram B. This is still not 100% accurate, but I think that expanding the move tree further will result in a net score that is within 0.5 points of that estimate.

Click Here To Show Diagram Code

[go]$$W D: net score 2 points
$$ ----------------------------
$$ . . . . . T T T . . S S . |
$$ . . . . . T T 2 X O O S . |
$$ . . . . . . . X O 1 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Or we can consider your diagram an alternative for diagram C (i.e. black will take sente if white connects), as in diagram E.

Click Here To Show Diagram Code

[go]$$W E: net score -6.5 points (back-tracked from diagrams F and G)
$$ ----------------------------
$$ . . . . . . . . 5 . . . . |
$$ . . . . . . 4 3 X O O . . |
$$ . . . . . . . X O 1 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

If we assume that white 5 in diagram E will be sente, the net score is about -4 points (2 + -6) [diagram F].

Click Here To Show Diagram Code

[go]$$B F: net score -4 points
$$ ----------------------------
$$ . . . . . T 1 . O S S S . |
$$ . . . . . T X O . O O S . |
$$ . . . . . . . X O O # O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

If we assume that white 5 in diagram E will be gote, the net score is -9 (-2 + -7) [diagram G].

Click Here To Show Diagram Code

[go]$$W G: net score -9 points
$$ ----------------------------
$$ . . . . 4 3 1 5 O S S S . |
$$ . . . . 6 2 X O S O O S . |
$$ . . . . . . . X O O # O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

So the net score for diagram E is the middle of the net scores of diagram F and diagram G = -6.5 points, which I included in the label of diagram E.

From this, my conclusion is that your proposed black atari loses about 1.5 points for black compared to diagram C, unless black still takes gote by continueing as in diagram D, which is more or less neutral compared to diagram B.

I'll readily admit that my score evaluations may be off by fractions of a point when analysed exhaustively. But who has time for that in a real game, and does it matter when the game is not a half-pointer?


Local gote or not may depend on the rest of the board. The provided position is not the whole board, so taking the average is an approximation. It's all I can do with the information provided.


I don't know. This is what I understood from his lessons. I don't claim to be an endgame expert, but what I descibed above seems practical and good enough for me to apply in my own games.
But I don't think an exhaustive evaluation will change the answer to the original question if b is better than a. No it isn't, but if black responds to a as in diagram B or D, the net score will be the same as in diagram A (net score 2 points).
So in a sense a is also sente (when the ambient temperature is below 7 points).

gennan,

the following things you make right:

- You use negative numbers for White's points as I do, IIRC Bill Spight has done and, by convention, one would do in maths.

- You approximate by ignoring detailed follow-up variations and dissecting sequences into their individual moves, what usually is acceptable for pragmatic reasons.

- You do not describe clearly that you are doing so but you do it at least implicitly: a gote sequence continued by a sente sequence follow-up (privilege) inherits the count after to before the sente sequence follow-up.

You invent the phrase 'net score' for what I call the 'difference value'. Both have disadvantages. Yours is that 'score' has a very specific meaning and one should not create confusion by a too similar name of a different term.

You make, in particular, the following conceptual(!) mistakes:

- Writing, say, (2 + -5) is not proper maths annotation but (2 + (-5)) is, as you should have learnt at school.

- You do not distinguish and determine the sente and gote types of a local endgame in every particular position. You use the words sente and gote in an informal sense related to assuming whether an answer is made [to create an alternating sequence of even or odd length].

- Consider your position created in E. Your position F is Black's gote sequence continuation to the count -4. Your position G is White's sente sequences continuation to the count -9. You derive the count of the position created in E as the average -6.5. This alleged count calculated as the average would be right if the position created in E was a local gote endgame. However, a local gote endgame is one in which Black has a gote sequence and White has a gote sequence. However, G has a sente sequence. Therefore, the position created in E must inherit the sente count -9.

Does Inseong Hwang's go school teach you all those conceptual mistakes, are they all yours or which are whose?

EDIT 2: adapted your corrected values and better interpreted your calculations of positions E F G.

In your EDIT you write: "Local gote or not may depend on the rest of the board."

Local evaluation of counts, move value, gains and (if there are local gote versus sente options) the gote-sente-difference does not(!) depend on the rest of the board. The decision of how (what options) and how long to play locally can (and often does) depend on the global environment.


See also EDIT 2 of my previous message.

Yes, I'm not too well informed about the terminology. I don't remember InSeong being very specific on terminology, but I don't think he uses terminology like 'net score' or 'difference value'. Perhaps his teachers weren't very specific on terminology either, or there may be a language barrier.
I'll keep using 'net score' in my posts in this thread to maintain consistency between my posts.


I think Dutch school maths notation is not as strict. I think that the spacing in the expression "2 + -5" would be accepted by most (including most maths school teachers) as clear enough that the " + " is a binary operator (addition) and the "-" is a unary operator (negation), which takes precedence over binary operators even without parentheses.
Also in computer programming the expression would be evaluated like that, with or without parentheses. So I would also leave those parentheses around -5 out when programming, to avoid clutter.
Ofcourse I could also just have written "2 - 5" instead of "2 + -5", but I thought that notation might be less clear about the reasoning behind it.


You are right. InSeong didn't teach me wrong, it's just my mistake in executing what he teaches (I tried to provide a caveat in my first post that any mistakes are most likely mine, not his).
Diagram G is indeed white's privilege after reaching Diagram E, so the net score of Diagram E should be -9 points, as you said.

So we have this:

Click Here To Show Diagram Code

[go]$$W E: net score -9 points (back-tracked from diagram G)
$$ ----------------------------
$$ . . . . . . . . 5 . . . . |
$$ . . . . . . 4 3 X O O . . |
$$ . . . . . . . X O 1 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

...versus this:

Click Here To Show Diagram Code

[go]$$W D: net score 2 points
$$ ----------------------------
$$ . . . . . T T T . . S S . |
$$ . . . . . T T 2 X O O S . |
$$ . . . . . . . X O 1 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

From diagram E and D, I think we can take the middle between -9 points and 2 points = -3.5 points for diagram H?

Click Here To Show Diagram Code

[go]$$W H: net score -3.5 points (back-tracked from diagram E and D)
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . X O O . . |
$$ . . . . . . . X O 1 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Then we can compare diagram H to diagram J with net score 7 points (8 + -1) :

Click Here To Show Diagram Code

[go]$$B J: net score 7 points
$$ ----------------------------
$$ . . . . . T T T . . . S . |
$$ . . . . . T T T X O O . . |
$$ . . . . . . . X Q 1 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

From diagram H and J, I think we can take the middle between -3.5 points and 7 points = 1.75 points for diagram K?

Click Here To Show Diagram Code

[go]$$W K: net score 1.75 points (back-tracked from diagram H and J)
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . 2 1 O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Then we can compare diagram K with diagram B:

Click Here To Show Diagram Code

[go]$$W B: net score 2 points
$$ ----------------------------
$$ . . . . . T T . . . S S . |
$$ . . . . . T T 2 . 1 O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

So in the end, diagram K seems slightly worse for black than diagram B (by 0.25 points), so black's atari may not be optimal endgame. But for a really accurate evaluation, I suppose diagram B needs further analysis of follow-ups, which may lead to a fractional adjustment of its net score, though I don't expect the result to be worse for black than net score 2 points.

Edit: I made multiple edits to this post, but I think I'm done now.

Absolutely not! A count of either player's follower could be positive, zero or negative. Therefore, we must not combine signs prematurely. Doing so nevertheless is suggested only by lazy people unaware of the general possibility, or worse, actively deceiving readers about fake simplicity.



No. An average is not for White's one sequence comparing White's other sequence but, once more,

A COUNT CALCULATED AS THE AVERAGE IS FOR A LOCAL GOTE ENDGAME HAVING BLACK'S GOTE SEQUENCE VERSUS WHITE'S GOTE SEQUENCE.

You have to start AFTER White's initial move!

Click Here To Show Diagram Code

[go]$$B D': count 2 (Black's gote sequence)
$$ ----------------------------
$$ . . . . . T T T . . S S . |
$$ . . . . . T T 1 X O O S . |
$$ . . . . . . . X O O X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Click Here To Show Diagram Code

[go]$$W E': count -9 (White's gote sequence, back-tracked from diagram G)
$$ ----------------------------
$$ . . . . . . . . 3 . . . . |
$$ . . . . . . 2 1 X O O . . |
$$ . . . . . . . X O O X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Now, for the position after White's first move there:

Click Here To Show Diagram Code

[go]$$W H': count -3.5 (back-tracked from diagrams D' and E')
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . X O O . . |
$$ . . . . . . . X O O X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

If all our earlier assumptions were right, the gote count of H' would be (2 + (-9)) / 2 = -3.5.

However, in particular, we still do not know if White's sente option might be better:

Click Here To Show Diagram Code

[go]$$W White's sente option
$$ ----------------------------
$$ . . . . . . 4 3 1 5 . . . |
$$ . . . . . . 6 2 X O O b . |
$$ . . . . . . . X O O X O . |
$$ . . X , . X . X X X a O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Black a - White b is a privilege.

***

We need to decide between gote and sente options. Afterwards, we need to back-track White's first move and compare with J.



We do not have enough analysis yet to proceed to answering this question.

The subject of this topic is "Gote move vs sente move in yose". This issue is of major importance in yose and in a game betweeen a professionnal and an amateur I guess the professionnal will often gain more than 10 points by a far better handling of this notion.
I agree with Robert : you cannot take the average value of a net score after a sente sequence and a gote one.
As an amateur I agree with you Gennan I always avoid an accurate count for two reasons: firstly an accurate evaluation is too time consuming for me, and secondly it is very easy to to be wrong somewhere when a lot of positions are involved.
The best I can suggest is to consider only the logical follow-up sequences assuming the result will be very near from the ideal calculation.

Click Here To Show Diagram Code

[go]$$B Black to play
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . a b O O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Let me show you how I answer my question concerning the choice between black a or black b in the above diagram.

Click Here To Show Diagram Code

[go]$$B Position after black a
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . 1 3 O O . . |
$$ . . . . . . . X O 4 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

After black I simply consider that black will be later able to play in sente with white answering

Click Here To Show Diagram Code

[go]$$B Position after black b
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . 3 1 O O . . |
$$ . . . . . . . X O 2 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Here after I consider white will be later able to play in sente with black answering

My conclusion is that black "a" and black "b" in the first diagram of this post are equivalent (net value +2)

It remains my initial question:

Click Here To Show Diagram Code

[go]$$W White to play
$$ ----------------------------
$$ . . . . . . . b . . . . . |
$$ . . . . . . . . . a O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

what is the best move for white ?

I did not consider that option for white. Indeed it should be included in the analysis.


OK, but shouldn't we then also consider a different move for white than connecting with , like so?

Click Here To Show Diagram Code

[go]$$W white's alternative?
$$ ----------------------------
$$ . . . . . . . . 1 . . . . |
$$ . . . . . . . . X O O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Click Here To Show Diagram Code

[go]$$W continuation?
$$ ----------------------------
$$ . . . . . . 4 3 1 5 . . . |
$$ . . . . . . 6 2 X O O b . |
$$ . . . . . . . X O a X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

If white takes sente after , a will be black's privilege, reverting to a net score of 2 points (more or less the same as diagram A as it was corrected by you, where white started with the first move at ).
If white takes gote by playing at a, it will revert to Robert's diagram above with net score 0 points (2 + -2).

I don't know yet if the evaluation is the same for black's atari and black's descent.

Click Here To Show Diagram Code

[go]$$ which is better for black?
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . a b O O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Perhaps it doesn't really matter, except that black b gives white more viable options than black a?
Maybe also for your original question, the only difference is that white a gives white more viable options than white b?

I agree with you gennan.

Click Here To Show Diagram Code

[go]$$W white's alternative?
$$ ----------------------------
$$ . . . . . . . . b . . . . |
$$ . . . . . . . . X O O . . |
$$ . . . . . . . X O a X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

In this diagram white can choose to take sente by playing either white "a" or white "b" with the same result (net score = +2).

For me this confirm that, in the following diagram, the black move at "a" and the black move at "b" are both gote and lead to the same result (net score = +2). Don't you agree?

Click Here To Show Diagram Code

[go]$$
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . a b O O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

To humour myself, I tried to peek KataGo's thoughts on the position.

In this position, my KataGo seems to think that black c is slightly better than both black a and black b. I hadn't thought of black c yet, but it's an interesting move.

Click Here To Show Diagram Code

[go]$$B
$$ ----------------------------
$$ . . . . . . . . c . . . . |
$$ . . . . . . . a b O O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

Black c does make sense, because white c is also a good move in response to black a or b, suggesting that c is a vital point.

From black c we can again evaluate a net score of 2 points (4 + -2)

Click Here To Show Diagram Code

[go]$$B
$$ ----------------------------
$$ . . . . . T T 5 1 4 S S . |
$$ . . . . . T T 3 2 O O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

And I suppose this variation is also the same result:

Click Here To Show Diagram Code

[go]$$B
$$ ----------------------------
$$ . . . . . . . . 1 . . . . |
$$ . . . . . . 5 2 3 O O . . |
$$ . . . . . . . X O 4 X O . |
$$ . . X , . X . X X X d O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

In the diagram above, black has 5 points, while white has either 1 or 5 points (so 3 points on average), depending on who plays d double gote first: net score is 2 points (5 + -3).

Yes, I agree. Even though KataGo may have slight preferences for one over the other, I think that black a, b and c all give the same result of net score +2.

With all those moves having the same value, the only advantage I can see for one move over the other is perhaps how many good options you are giving your opponent to reach an optimal result, and how easy or difficult it is to find those good options. And perhaps there may be a difference in ko threats between different variations?

Other than that, I now agree with your very first post in this thread, where you disputed the author's claim.
Although I wonder if you'd still call the best move according to the author a gote move, because we seem to converge on it being a sente move.

I agree with you Gennan, the three black moves a, b, and c give the same result (net score +2).
Having seen the work of Gennan on this position above I was OC happy to have a discussion looking for the best black move in such position and it is quite satisfactory to see that we reached a common understanding.

Now let's return to my initial question:

Click Here To Show Diagram Code

[go]$$W White to play
$$ ----------------------------
$$ . . . . . . . b . . . . . |
$$ . . . . . . . . . a O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

What is the best white move a or b?
Considering this initial question, I consider the previous analysis as only another exercice on the topic on this thread.

Let me give you only the beginning of my analysis:

Click Here To Show Diagram Code

[go]$$W White to play
$$ ----------------------------
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . 1 O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

For me the white move above is a big move made in a position where the temperature is probably equal to 10 points if not more!
After this move my intuition (or my go experience) tells me that the temperature has now decreased and as a consequence black will play tenuki. That means that white will then be able to play the following sequence in sente:

Click Here To Show Diagram Code

[go]$$W
$$ ----------------------------
$$ . . . . . 6 5 7 . . . . . |
$$ . . . . . 0 4 3 9 1 O . . |
$$ . . . . . . . X O 8 X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

As you see my analyse does not take into account a black move after white which is a major simplification.
How do you continue the analysis to find what is the best first white move?

Suppose the reverse sente count R, and we do have a gote option and a sente option indeed with their resulting counts A and B, respectively, where, since White is the creator, A ≤ B < R.

Calculate / determine the
- gote move value of the gote option,
- follow-up move value of the sente option,
- possibly sente move value of the sente option,
- possibly gote-sente-difference B - A.
- temperature T, and
- possibly second-largest environmental move value T1.

Third, apply the theory in [22], [23] of Bill Spight and me to decide whether to play elsewhere, locally with the gote option or locally with the sente option.

https://www.lifein19x19.com/viewtopic.p ... 45#p143245

Robert, you know perfectly that on many occasions in the past I tried to use your theory or Bill's theory but unless the position is very simple I always failed to give the correct answer for two reasons : firstly the method is too complicated and needs too much time to be used in a practical game (see what you have listed yourself in your post under "Calculate / determine the") and secondly the local position is rarely clearly defined for applying a pure theoritical method and you will be always able to critisize (and you will be right!) any assumption for simplifying the analysis.
As an example:

Click Here To Show Diagram Code

[go]$$W White to play
$$ ----------------------------
$$ . . . . . . . 1 . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . X O . X O . |
$$ . . X , . X . X X X . O . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . O . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . O . . |
$$ . . . , . . . . . , . . . |[/go]

If I claim white is sente I am quite sure you will contredict me by saying it will depend on the exact configuration of black on the upper side and of course you are right aren't you?

No Robert, unless you show yourself, on this practical example, how you can apply your method, I consider it is a valuable pure theorical approach but completly inapplicable in practice (unless for quite obvious positions OC). It is up to you to prove you can yourself apply it with the position I proposed in this thread. I am unable to help you on this point.

We can make an agreement on what assumptions not to verify (such as B shall be sente and gennan's earlier value -9 shall be correct, which I have not verified).

However, to apply theory instead of just guessing(!) which move might be right, it is mandatory to calculate the aforementioned values at least approximately. (Depending on the case, it can be sufficient to calculate only some particular ones.) This calculation is what takes the time because the local values depend on sequences and positions, which must be constructed and annotated carefully to avoid big evaluation mistakes, as you could already see so far. If it shall be clear enough to convince everybody at least as an approximation, for every such complicated shape example, it takes hours to compose, annotate and use for calculation the sequences and positions.

Time that I do not have. I am more than busy with work and private matters. The time for doing these things preceding application of the theory must come from you other users here.

When the necessary values will have been calculated at least approximately, then application of the theory only takes minutes so then I will be able to take the time and do it.

If you absolutely want me to do all the work of every overly complicated example you show, you need to pay me for my spent time so that I do not starve. Seriously. Time I cannot spend on work loses income. It is 2 pm here and I have worked all day before my breakfast now. This is how little time I have.

Why must you often start from too complicated positions to show off the real game world? Can you not start from a simplified example for which application of the theory is fast, let us apply it, then slightly modify the position to add some first complication, let as discuss necessary approximation, then iterate until eventually reaching real game complications? You act like life and death book problems are beneath you because they are not as complicated as real game life and positions. We cannot solve everything and even quickly just because it is realistic.

If you want guesswork solutions, use the method of reading and counting for your whole board position: emulate the gote option and see a count of a follow-up quiet position; do so also for the sente option; compare! No too-time-consuming theory needed! Approximation only but you have declared to prefer it anyway.

I fully agree with you Robert : applying theory for such position is far too time consuming. I perfectly understand you do not want to lose time applying the theory in such position and you have to understand that I also do not want to apply theory for such position, for exactly the same reason. In this context can you simply avoid suggesting applying this theory you do not accept yourself to use because it is too time consuming? In practice you can hardly take more than 5' to decide whether you will choose a sente option rather than a gote one in a local position.

Note that in my very first post of this thread I did not suggest to apply this inapplicable theory, I was only looking for your view as go player (not as yose theoritician) when you have to choose between the gote move "a" and the sente move "b".

BTW Robert, assume you are really able to stricly apply the theory. Assume you calculate that a sente option will gain 7 points while a gote option will gain (only) 13 points. You will guess that the sente move should be the best option but you might be wrong in practice because the environment is rarely ideal.

As a theory, be sure I consider it as very valuable, but in practice it is for me completly inapplicable.

In practice I guess each player has developped her own evaluation method and for sure I will never say that my own approach for the calculation is the best one.

This is your wrong interpretation of my choice. My choice is a) to not always spend much time whenever somebody else (in this case: you) wants me to spend much time and b) to spend much time when I want to, and can, do so on my own (E.g., during playing my own game and I have enough thinking time left. E.g., in a recent tournament game with ca. 90 minutes basic time left, I spent 60 minutes on one position's large, game-deciding life and death problem. I tried, did a pretty good job at reading but still failed - but if I had succeeded at completing the reading correctly to its deepest ends only then involving rare tesujis, I would have won the game.).



In the simplest case of a high temperature, the creator chooses the gote option or tenukis so we might ignore the sente move value. In that case, all we need of the sente option is (an approximation of) the follow-up move value to verify that indeed the temperature is high. Determining this and (an approximation of) one initial move value (the one of the gote option) should be possible within 5 minutes.



LOL. Like my endgaming was as a low dan confusing gote and reverse sente. It was my own method but the error was at least the factor 2. Or just guessing move values - was as bad.

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