This post follows on from the "which side to play atari" post. It shows
situations where White needs to save one or more stones in atari. He must
choose to extend or capture. The White player (me) usually makes
the wrong choice according to KataGo.
In the above diagram, the circled stone is in atari. I played at a,
but b is 8.9 points better according to Katago. I was worried about
the potential (indirect?) ko if Black replies to b at a, but
failed to notice that Black can gain a liberty in the capturing race after
White a by playing b himself, which gives Black a better squeeze
on the squared white stones.
In the above diagram, the marked stones are in atari. I played
a, but b is 0.8 points better according to Katago. That is a
significant difference this late in the game. The reason is that White b
forces Black c, which I had not noticed. If Black does not answer
b at c, White makes further gains by pushing in at d.
I often have trouble seeing what is what late in the game when the visual field
is busy, as here. This is true whether playing online or over the board.
Katago sees clearly and invites me to think.
In the above diagram, the marked stone is in atari. I played a,
which is 1.5 points better than b. However, KataGo thinks that White c
is best here. (Even when you are right, you are still wrong.)
In the above diagram, the marked stone is in atari. I played a, but b
is 3.8 points better according to Katago. This shape often occurs on
the second and third lines, and I have noticed that strong players usually
capture the opponent's stone.
In the above diagram, the marked stone is in atari. I played
a, but b is 2.4 points better according to Katago. The
situation is similar to that in the previous diagram.
Review
There is not enough material to draw any general conclusions. However,
accurate reading always helps, and one should probably capture any cutting
stone on the third line immediately if possible.
Retraining the Neural Network in My Head - Part 2
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thirdfogie
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Re: Retraining the Neural Network in My Head - Part 2
In these sorts of atari situations, I believe that in general stronger (let's say 1d) players are much more likely to just capture a stone, and weaker (let's say 5k) players are more likely to extend instead of taking the stone off the board, which looks more efficient but often leads to the opponent getting forcing moves later or having some aji still around. I think that it is a good instinct for players of our level to first consider making the capture, unless there is clearly zero aji.thirdfogie wrote:There is not enough material to draw any general conclusions. However, accurate reading always helps, and one should probably capture any cutting stone on the third line immediately if possible.
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jlt
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Re: Retraining the Neural Network in My Head - Part 2
To decide whether to extend or capture, I try to imagine the followup. Consider the following diagram.
If White plays at "a" then
is forcing. 
plays elsewhere because any local move is gote, then White comes back later to play 
with sente.
If White plays at "b" then plays elsewhere, but then White has sente endgame moves.
If White plays at "a" then
is forcing. plays elsewhere because any local move is gote, then White comes back later to play with sente.If White plays at "b" then
plays elsewhere, but then White has sente endgame moves.-
dfan
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Re: Retraining the Neural Network in My Head - Part 2
I believe that for this reason Black usually forces withjlt wrote:If White plays at "b" then
first, since White won't be able to make as much progress with a in the following diagram:Confirmation or disagreement from stronger players would be appreciated!
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Re: Retraining the Neural Network in My Head - Part 2
Good point. I just asked KataGo now and it wants to first play the double sente sequence starting with E2, then come back and play my .
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Re: Retraining the Neural Network in My Head - Part 2
It was the prospect of a ko if white plays elsewhere after that made me extend
instead of capturing during the game.
Extending was clearly a mistake in this game because White is so strong to the left of the
potential ko that he has nothing to fear from Black starting it. In the general case, it
feels burdensome to have to evaluate a potential ko before making the "extend or capture"
decision, so I will adopt the "Ape stronger players" policy and hope to learn by
experience if any exceptions do appear.
that made me extendinstead of capturing during the game.
Extending was clearly a mistake in this game because White is so strong to the left of the
potential ko that he has nothing to fear from Black starting it. In the general case, it
feels burdensome to have to evaluate a potential ko before making the "extend or capture"
decision, so I will adopt the "Ape stronger players" policy and hope to learn by
experience if any exceptions do appear.
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Re: Retraining the Neural Network in My Head - Part 2
sequence is questionable as white can use black's shortage of liberties around E5 instead.)next diagram - explained very well by others. Even if black were solid elsewhere on the board, I would be very reluctant to sacrifice the chance to get into black's upper right corner just to avoid a (medium size) ko that black has to spend 2 moves to start. The ko isn't that small, but black is so thin in the upper right. In this game, black's shape on the left seems to have some problems and some ko threats, or at least threats to set up ko threats (in order to profit), or to get endgame such as E2.
Last edited by dhu163 on Sun Apr 11, 2021 8:24 am, edited 1 time in total.
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John Fairbairn
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Re: Retraining the Neural Network in My Head - Part 2
An interesting exercise.
Have you got any inkling as to why this bias may be so. E.g. did someone give you bum information in the past, or did you lack playing over enough pro games (i.e. you did not previously train your neural network on the basis of pro games)? Or perhaps there are other psychological factors, such a being more concerned with depriving the opponent of something rather than attending to your own concerns? (I happen to believe this last point is something that applies to ALL amateur play.)The White player (me) usually makes the wrong choice according to KataGo.
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Re: Retraining the Neural Network in My Head - Part 2
Thanks to everyone who commented.
John Fairbairn
It feels like the mistakes spring from the last of your causes: giving too
little priority to weaknesses in my own positions. I haven't played over
any professional games on a real board since September 2013, when my wife
was away for a month. Watching professional games online is clearly not
the same thing.
We are told that passive play is a sure road to defeat, and it may be that
I take that advice too simplistically. Sometimes, "reculer pour mieux sauter"
should be the motto. Or one could simply blame egotism.
dhu163
Thanks for the detailed analyses. I am amazed that anyone could apply end-game
mathematics to the game shown below, given that he must first identify all the
candidate sequences. On the other hand, people have composed great music using
six-part counterpoint and performed highly abstract mathematics in a way which
makes me gasp for breath, so what do I know? The diagram shows KataGo's best moves
following White's mistake. Model b40c256-s6485784576-d1573360039 was used
with about 30,000 visits per move, though the number of visits seems to make
little difference this late in the game. White has a lead of about 11 points,
but KataGo still picks the mathematically best moves as far as I can tell.
In the actual game, black played 1 and I replied with a grotesque self-atari
(white at black 5). After that, I was lucky to win by 2 points.
In the following game, my original comment on the situation was wrong.
I should have analysed more with KataGo before posting. The continuation
is what actually happened. Black's terrible mistake at 5 may be
instructive for some.
John Fairbairn
It feels like the mistakes spring from the last of your causes: giving too
little priority to weaknesses in my own positions. I haven't played over
any professional games on a real board since September 2013, when my wife
was away for a month. Watching professional games online is clearly not
the same thing.
We are told that passive play is a sure road to defeat, and it may be that
I take that advice too simplistically. Sometimes, "reculer pour mieux sauter"
should be the motto. Or one could simply blame egotism.
dhu163
Thanks for the detailed analyses. I am amazed that anyone could apply end-game
mathematics to the game shown below, given that he must first identify all the
candidate sequences. On the other hand, people have composed great music using
six-part counterpoint and performed highly abstract mathematics in a way which
makes me gasp for breath, so what do I know? The diagram shows KataGo's best moves
following White's mistake. Model b40c256-s6485784576-d1573360039 was used
with about 30,000 visits per move, though the number of visits seems to make
little difference this late in the game. White has a lead of about 11 points,
but KataGo still picks the mathematically best moves as far as I can tell.
In the actual game, black played 1 and I replied with a grotesque self-atari
(white at black 5). After that, I was lucky to win by 2 points.
In the following game, my original comment on the situation was wrong.
I should have analysed more with KataGo before posting. The continuation
is what actually happened. Black's terrible mistake at 5 may be
instructive for some.
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John Fairbairn
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Re: Retraining the Neural Network in My Head - Part 2
This interests me because it is a language thing rather than a maths thing. Without getting into Sapir-Whorf arguments I do believe there is a link between language and actions.We are told that passive play is a sure road to defeat, and it may be that
I take that advice too simplistically. Sometimes, "reculer pour mieux sauter"
should be the motto. Or one could simply blame egotism.
The reason this particular post of yours interests me is that you say someone has been telling you that passive play is to be avoided. But who? I've racked my brains but I can't recall the word passive being used in oriental texts. Very occasionally there are words that tend in that direction (e.g. "negative"), but these are very occasional, and my gut feeling is that such comments are applied to beginners far, far more than to stronger players.
But, in contrast, what I notice is ultra-common in pro talk are references to timing.
To be specific, if we take the atari on the outside and the atari on the inside in your first example, what came over to me was an attempt to say one is better than the other in some static way. In your case this may be because you apparently perceive one as potentially aggressive or passive, but I could easily imagine others may say it's a matter of good and bad shape, for example.
However, my impression from pro talk is that neither is better or worse than the other in such terms. Nor is it, perhaps strangely, a matter of reading. Rather, it is a matter of timing. We can infer this from the fact there are so many comments of the type "Black should first play A, then B". In other words, purely in shape terms B is not at all inferior - it's just inferior at this particular moment in terms of timing. Furthermore, this can be but does not have to be the same as gote no sente (or reculer pour mieux sauter). That is, timing issues are pervasive - they are not just honte moments.
As some mild proof of that, I used Kombilo to check the position of two different-coloured ikken-tobis side by side with one side wedging between the opposing ikken. Kombilo came up with lots of examples in the 110,000-game GoGo database - and the inside and outside ataris as played by pros came up exactly even!
In short, I think we vastly overate shape and underestimate timing in go. It may be time to revisit Juergen Mattern's Der richtige Zeitpunky? It's a very long time since I read that and I can't remember what's in it. Does anyone have a more recent memory?
But, in general, what do you think of exploring the notion of timing more.
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Uberdude
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Re: Retraining the Neural Network in My Head - Part 2
I think the relative abundance of discussions on timing in pro commentaries in pro games, does not necessarily mean it should be of the same abundance and importance in commentaries on kyu games. Kyus make gross mistakes (chief categories being massive underplays aka passive play, and also massive overplays / over-aggression) that pros left behind many years ago when still little kids. So of course pros aren't going to be talking about things like wasting a move to live with a group that was already alive, or how to kill a bulky 5, or not playing a 2 point move in the opening when there are 30 point moves up for grabs, because that's super easy and obvious for them. Timing is one of the more advanced topics which they can still get wrong and differ in opinions, so they talk about it more.John Fairbairn wrote:<snip>We are told that passive play is a sure road to defeat, and it may be that
I take that advice too simplistically. Sometimes, "reculer pour mieux sauter"
should be the motto. Or one could simply blame egotism.
But, in contrast, what I notice is ultra-common in pro talk are references to timing.
This is not to discourage more talk of timing here, it's a fascinating topic and indeed one of my favourite books "Beyond forcing moves" could be subtitled "the importance of timing". Here's a thread about a critical timing issue in a common post-joseki joseki viewtopic.php?f=17&t=5150.
I find it interesting that thirdfogie says he was trying to avoid passive play as his justification for the extend here (or maybe in general and not this example?): I would characterise this mistake as being passive! To illustrate, with a simple tewari: white instead captures at 1, black descends at 2, white then answers at 3, kindly giving black the large endgame move at 2 in sente. 3 is, I think we can all agree, terribly passive, much better to tenuki and play elsewhere. But by extending at 3 first, this is the result you get.
So the only reason to not capture for 1, is if you think black won't play descend for 2, but will play the atari for a ko and you don't like that.
But if you are scared of ko don't play go! as the saying goes. So I would actually say the descend is more accurately described not as avoiding passive play, but avoiding a scary looking ko (which stronger players know isn't scary, because wimping out of that ko is admitting defeat without a fight).It was the prospect of a ko if white plays elsewhere after
instead of capturing during the game.
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dhu163
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Re: Retraining the Neural Network in My Head - Part 2
Its late enough in the game that I think CGT theorists could solve it perfectly with some time and maybe a computer. As for me:I am amazed that anyone could apply end-game
mathematics to the game shown below, given that he must first identify all the
candidate sequences.
Well, the KG diagram means I got it wrong all over the place. I haven't put in enough study of the endgame myself and I'm learning here too. I normally only use approximations, which is insufficient for accuracy on the whole board. But there are also several things I still don't understand with KG's diagram.
I didn't notice the tesuji that means
is big. The tesuji is black can play two spaces above , that gains around 1 1/3 in sente or 4 in gote with a crude atari. The fact there is this big move breaks my argument already.I didn't notice black could clamp in the upper left gaining around 1 2/3 in sente locally, but a bit less as it concerned the ko to the right of it.
White connecting in the centre is a 2 point reverse sente, so isn't immediately clear why
is better (or perhaps it is just a matter of style and both are fine).The descent in the lower right is also big, and as far as I can tell black hane is 3 to 4 points in gote.
I guess there isn't much point for black to take a reverse sente when white can also take a reverse sente, so my logic for my diagram was wrong.
E5 still seems hard to evaluate. Because even after the
exchange in your diagram, the next move is still pretty big, 3 points gote at E6.-
thirdfogie
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Re: Retraining the Neural Network in My Head - Part 2
This post is to tidy up some loose ends and act as a reference if I ever need to revisit
the topics.
dhu63 during the game. He has started looking for moves like
this on the first line.
John Fairbairn
is that my opponent plays the wedge when it is a bad move. The
professional-standard moves you examined would presumably not be giving the
opponent a chance to make a big gain.
"idiotically". The kind of advice I had in mind is "Do not follow
the opponent around the board" and "If the opponent plays a so-called
double-sente move, look for a similar move you can play elsewhere". No doubt
both rules are too simple as stated, but I have certainly found them useful. I
cannot read oriental texts, so cannot quote original professional-level
material if that is what you were asking for. Yoon YoungSun does have a recent
post (https://www.youtube.com/watch?v=8LrJF6huDso) with the strap-line
"Effective and Aggressive Haengma", where she discusses responses to an
opponent's peep. She is really explaining efficient responses, but the word
"aggressive" is there, alongside a cartoon crocodile.
Be that as it may, John's reply prompted a wider survey on my side. A search
of 64 older games against the same opponent were found to contain 26 wedge moves
by him and 7 by me. Details of the search are hidden below.
In the 64 games examined, there were 26 wedge moves by him and 7 by me.
All but 2 wedges were bad according to KataGo. It would be too much work to
make a diagram for all of them, and one should not spam the forum with
examples of bad play. Excruciating details are hidden below.
Of the 23 non-obvious cases where my opponent wedged, 7 of my replies were
wrong and 16 were right. One reason I did better against this collection of
wedges than in the original 4, is that 7 wedges in the second set happened in
shapes that are familiar from joseki or middle-game joseki, and all my replies
were correct in those cases. (I know very few joseki but my opponent
makes a virtue of knowing none.)
Of the same 23 cases, the "outside" move was correct in 13 cases, the "inside"
move was correct in 9 cases. In the other 2 cases, it was not possible to say
which side was "outside". Taken together with the 4 cases in the original
post, there may yet be some value in my original idea that "playing the
outside atari" is often better against this particular opponent. My
idea of "outside" is a vague blend of "towards the centre of the board" and
"away from the opponent's strength".
In the 7 cases where I wedged, 2 were correct. In 2 of the other 5, the best
move for white was actually a clamp. That discovery alone justifies the
exercise.
I don't regret spending time on the research, but it has now been overtaken by
events. My opponent has access to these findings and has stopped playing
wedges. He now favours lots of invasions on the first line, which are easier
to read out. Meanwhile, I am blundering away won games by not counting
liberties when tired near the end of the game. It is unclear how to cure that
ill.
the topics.
dhu63
My opponent foundI didn't notice the tesuji that means
two spaces above
during the game. He has started looking for moves likethis on the first line.
John Fairbairn
Thanks for checking with Kombilo. Your results were salutary. One differenceI used Kombilo to check the position of two different-coloured ikken-tobis
side by side with one side wedging between the opposing ikken. Kombilo came up
with lots of examples in the 110,000-game GoGo database - and the inside and outside
ataris as played by pros came up exactly even!
is that my opponent plays the wedge when it is a bad move. The
professional-standard moves you examined would presumably not be giving the
opponent a chance to make a big gain.
You perhaps inferred too much. My word "simplistically" should have beenThe reason this particular post of yours interests me is that you say someone
has been telling you that passive play is to be avoided. But who? I've racked
my brains but I can't recall the word passive being used in oriental texts.
Very occasionally there are words that tend in that direction (e.g.
"negative"), but these are very occasional, and my gut feeling is that such
comments are applied to beginners far, far more than to stronger players.
"idiotically". The kind of advice I had in mind is "Do not follow
the opponent around the board" and "If the opponent plays a so-called
double-sente move, look for a similar move you can play elsewhere". No doubt
both rules are too simple as stated, but I have certainly found them useful. I
cannot read oriental texts, so cannot quote original professional-level
material if that is what you were asking for. Yoon YoungSun does have a recent
post (https://www.youtube.com/watch?v=8LrJF6huDso) with the strap-line
"Effective and Aggressive Haengma", where she discusses responses to an
opponent's peep. She is really explaining efficient responses, but the word
"aggressive" is there, alongside a cartoon crocodile.
Be that as it may, John's reply prompted a wider survey on my side. A search
of 64 older games against the same opponent were found to contain 26 wedge moves
by him and 7 by me. Details of the search are hidden below.
All but 2 wedges were bad according to KataGo. It would be too much work to
make a diagram for all of them, and one should not spam the forum with
examples of bad play. Excruciating details are hidden below.
wrong and 16 were right. One reason I did better against this collection of
wedges than in the original 4, is that 7 wedges in the second set happened in
shapes that are familiar from joseki or middle-game joseki, and all my replies
were correct in those cases. (I know very few joseki but my opponent
makes a virtue of knowing none.)
Of the same 23 cases, the "outside" move was correct in 13 cases, the "inside"
move was correct in 9 cases. In the other 2 cases, it was not possible to say
which side was "outside". Taken together with the 4 cases in the original
post, there may yet be some value in my original idea that "playing the
outside atari" is often better against this particular opponent. My
idea of "outside" is a vague blend of "towards the centre of the board" and
"away from the opponent's strength".
In the 7 cases where I wedged, 2 were correct. In 2 of the other 5, the best
move for white was actually a clamp. That discovery alone justifies the
exercise.
I don't regret spending time on the research, but it has now been overtaken by
events. My opponent has access to these findings and has stopped playing
wedges. He now favours lots of invasions on the first line, which are easier
to read out. Meanwhile, I am blundering away won games by not counting
liberties when tired near the end of the game. It is unclear how to cure that
ill.
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dust
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Re: Retraining the Neural Network in My Head - Part 2
Maybe you need to retrain your neural network to play so as to win games early and decisively.thirdfogie wrote: I don't regret spending time on the research, but it has now been overtaken by
events. My opponent has access to these findings and has stopped playing
wedges. He now favours lots of invasions on the first line, which are easier
to read out. Meanwhile, I am blundering away won games by not counting
liberties when tired near the end of the game. It is unclear how to cure that
ill.