John Fairbairn wrote: But if you view the board as four equilateral triangles
I usually don't view the board this way.
This 'n' that
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John Fairbairn
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Re: This 'n' that
Sorry, I was slipshod and used equilateral for isosceles. Like numbers, geometry falls into the class of things I have to stop and think about. The advantage is that I can often get away with bigger slices of pie.
I have written a lot about New Fuseki theory in Old Fuseki vs New Fuseki.
I have written a lot about New Fuseki theory in Old Fuseki vs New Fuseki.
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Bill Spight
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Re: This 'n' that
Dear John,
I think that we are going to have to rethink our ideas of thickness and influence because of go AI. And other concepts, as well.
As for dividing the board diagonally, didn't you say that Sonoda sometimes does that?
I think that we are going to have to rethink our ideas of thickness and influence because of go AI. And other concepts, as well.
As for dividing the board diagonally, didn't you say that Sonoda sometimes does that?
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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Aidoneus
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Re: This 'n' that
John Fairbairn wrote:I have written a lot about New Fuseki theory in Old Fuseki vs New Fuseki.
$168.54 for a used copy from Amazon is just a bit too steep for me.
Edit: I now have found the thread on your book. Too bad it seems to be out of print.
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Uberdude
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Aidoneus
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Re: This 'n' that
Uberdude wrote:https://www.schaakengo.nl/goshop-keima/books/books-by-publisher/slate-and-shell/ss59-old-fuseki-vs-new-fuseki-fairbairn
€10 plus postage
Thanks!
Edit: I just discovered that the book is available from SmartGo, so I bought the electronic version. Which I can begin reading right now.
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Bill Spight
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Re: This 'n' that
Very strange. In note #534 I wrote that White played 
, and when I go to edit it, that shows up, but in the note as it appears, it says that green played . Does the same thing happen here?
Edit: Yes, it does.
What about Black?
Edit: Black shows up as Purple.
Later edit: Corrected now. Thanks.
, and when I go to edit it, that shows up, but in the note as it appears, it says that green played . Does the same thing happen here?Edit: Yes, it does.
What about Black?
Edit: Black shows up as Purple.
Later edit: Corrected now. Thanks.
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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Bill Spight
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Re: This 'n' that
Direction of Play?
Basic diagram:
Just about every opening textbook has a diagram like this. The arrows indicate the direction in which each enclosure naturally develops. If Black plays on the left side first, she can play on C-10 and then, if White plays on C-12, Black can jump to E-10, forming an ideal box framework.
Below are positions from actual pro games with enclosure facing enclosure on one side. The textbook play appears to be the extension to the 10-3 point. Is that where the pros actually played? And is there a better play?
Since the title has a question mark, you might think that there is a better play. Anyway, food for thought. I'll reserve the next four posts for comments based upon the published Elf analysis.
Note that three of the games have no komi. In a no komi game the best practical play for White may be to make an overplay, an aggressive play, or to complicate the game. Conversely, Black may play safe, sound, and simple. Elf, OC, assumes a 7.5 komi.
Edit: It may come as no surprise that all the pros played the 10-3 extension, and that Elf preferred a different play in each case, to varying degrees.
White to play. 4.5 komi.
White to play. No komi.
White to play. No komi.
Black to play. No komi.
Basic diagram:
Just about every opening textbook has a diagram like this. The arrows indicate the direction in which each enclosure naturally develops. If Black plays on the left side first, she can play on C-10 and then, if White plays on C-12, Black can jump to E-10, forming an ideal box framework.
Below are positions from actual pro games with enclosure facing enclosure on one side. The textbook play appears to be the extension to the 10-3 point. Is that where the pros actually played? And is there a better play?
Since the title has a question mark, you might think that there is a better play.
Anyway, food for thought. I'll reserve the next four posts for comments based upon the published Elf analysis.Note that three of the games have no komi. In a no komi game the best practical play for White may be to make an overplay, an aggressive play, or to complicate the game. Conversely, Black may play safe, sound, and simple. Elf, OC, assumes a 7.5 komi.
Edit: It may come as no surprise that all the pros played the 10-3 extension, and that Elf preferred a different play in each case, to varying degrees.
White to play. 4.5 komi.
White to play. No komi.
White to play. No komi.
Black to play. No komi.
Last edited by Bill Spight on Tue Apr 09, 2019 6:41 pm, edited 4 times in total.
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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Bill Spight
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Re: This 'n' that
White to play. 4.5 komi.
Takagawa (of course, to those familiar with his play) took the C-10 point. Here are the next 10 plays.
extended on the top side, preventing a double wing formation by White. Play continued in a fairly standard way for the time.----
Elf evaluated
as losing 4%. But Elf's margin of error is around 4%, I think. It's high because Elf gives large error estimates, not because its winrate estimates are bad. So I think we can say that Elf considers to be questionable. To help us understand Elf's evaluation, let's compare Elf's main line after to its main line after 
.Elf thinks that
should attach to the top of (marked)! 
After 
let's evaluate the left side. Maybe White has gained about 1 pt. of territory, 2 pts. of actual territory for White vs. 1 pt. of central influence for Black. Compare that with the next diagram.With this exchange, White's moyo has gained around 8 pts. more than Black's has. OC, moyo is not territory, so maybe White has gained about 3 pts. more than Black, a couple of more points than in Elf's main line diagram.
White plays his preferred joseki in the bottom right. (Other bots might play the kosumi or keima.) Then Black plays the Go Seigen/AlphaGo shoulder blow, rather than an extension on the top side. (Well if Elf does not like the extension on the left side, why would it like one on the top side?
) 
surprised me. Since 
reduces the White moyo, why extend it? But AlphaGo, Elf, and other bots like the center. And this move nullifies Black's advantage there. (In particular it prevents a two step hane in the center. It also prevents Black E-13, threatening to connect either way.) 
and 
strengthen Black on the top side while still reducing the White moyo. Note that 
is an approach, not a wedge or pincer.Now let's take a look at Elf's main line after
.White plays his preferred joseki in the bottom right corner. Then Black plays an ogeima enclosure in the top right, distantly approaching the bottom right stones. "a" is a rival with approximately the same win rate estimate, but "a" only gets 26k playouts to 51k playouts for the enclosure.
approaches the top right corner. "a" and "b" have the same win rate estimates, but "a" gets only 17k playouts and "b" gets 5k playouts, while gets 22k playouts. Surely the left side extensions are playable at that point. is a close pincer. "c" is a rival, but gets only 3k playouts versus 17k.
finally makes the extension on the left side. The pincers "a" and "b" are rivals, with the same win rate estimates, but again it is a playout contest. "b" gets 3760 playouts and "a" gets 5230, while gets 5313, a very close call. 
plays the shoulder hit and 
taps it underneath to contest the top side.----
What seems to be going on is that Elf considers the extension for White to be premature at move 8, and perhaps prefers the attachment against the top left enclosure for Black. Perhaps it is an example of the dictum, corners before sides. Corners may remain urgent longer that we had thought.
And the top attachment against the White extension was an eye opener for me. It indicates that the extension may not be as large as the textbooks suggest.
Edit: Please note that the board in the actual game is rather more developed than in either of Elf's main lines.
Last edited by Bill Spight on Mon Apr 08, 2019 9:51 am, edited 10 times in total.
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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Bill Spight
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Re: This 'n' that
White to play. No komi.
Fujisawa Hideyuki (AKA Shuko) also played the 10-3 extension. The subsequent play has some notable features.
combined a 5 pt. extension from the enclosure with a 3 pt. extension from the Black stone in the top left corner. 
completed a double wing formation from the bottom left corner. When I was learning go, a double wing was supposed to be ideal, but pros, both at the time and historically, had not always rushed to prevent one. W"a" is a common response to the 
pincer, but Fujisawa chose to play a Kitani joseki, settling White into the corner. Then was a very high reduction of White's double wing, an unusual choice. Black may have been counting on the lack of komi to keep White from playing strongly against the reduction in exchange for a bit more territory.----
Elf considers
to be an 8% mistake, so it very probably is a mistake. As above, let's look at Elf's main line after and compare it with its main line after .Black plays the taisha in the top left corner. White takes territory in exchange for outside strength.
is a tesuji noted not long ago by John Fairbairn in human play in a different position. After Black retains sente and approaches the bottom right corner with 
. This approach to the high enclosure has a long pedigree.Now let's look at Elf's main line after
.As we may have anticipated, Elf considers the top left corner to be the hot spot of the board.
is the now standard keima. Black turns to the right side, but starts with the outside attachment to White's bottom right enclosure. After that kikashi Black extends to the 10-4 point. Again, "a" has the same win rate estimate, but loses the playouts, 5k to 22k. To me that makes sense, because the high extension looks good with the rest of the board, and because of the Black stones in the bottom right, Black is not concerned about a White play at "b". invades the bottom left corner. Black takes sente and returns to the the bottom right with the turn, . is a tesuji aiming to play at "a" or "b". As is often the case, Elf ends its variation in media res, leaving us to wonder how Black will reply. My main takeaway is similar to the last example, The corner is hotter than the side, even one with facing enclosures. This corner, with the 3-5 Black stone on the side closer to the Black enclosure instead of the lone 4-4 stone, seems to be hotter than the one in the Takagawa game, perhaps because a Black wall would work better with the enclosure, so that Elf considers the side extension to be a worse mistake.
BTW, Elf considers
in the actual game to be a 9-10% mistake, even worse than , returning the favor with interest. Both players, despite being among the world's best at the time, seemed to share an illusion about the value of those extensions, by comparison with a play in the top left corner.
Last edited by Bill Spight on Mon Apr 29, 2019 12:17 pm, edited 13 times in total.
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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Bill Spight
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Re: This 'n' that
{Under construction}
White to play. No komi.
Cho Chikun also played the 10-3 extension. Then Kono played the usual underneath attachment in the top left corner. The kosumi was standard when Black also had a strong, low stone to the right ( 
), to provide a high-low balance. was the standard blocking extension on the right side.
Cho approached the bottom left corner and then made a double wing formation with was a probe in the corner, and after 
pulled back, Kono played the invasion at .
{More analysis to follow.}
White to play. No komi.
Cho Chikun also played the 10-3 extension. Then Kono played the usual underneath attachment in the top left corner. The
kosumi was standard when Black also had a strong, low stone to the right ( ), to provide a high-low balance. was the standard blocking extension on the right side.Cho approached the bottom left corner and then made a double wing formation with
was a probe in the corner, and after pulled back, Kono played the invasion at .{More analysis to follow.}
Last edited by Bill Spight on Mon Apr 29, 2019 12:19 pm, edited 5 times in total.
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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Bill Spight
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Re: This 'n' that
{Under construction}
Black to play. No komi.
Shirae also played the 10-3 extension with. Sugiuchi (still active at age 92, see the Sugiuchi watch thread, viewtopic.php?p=241376#p241376 ) replied with , the standard checking extension on the right, only a two space extension because of the weakness of the ogeima enclosure. Black then pincered on the left side, and the battle continued there for several moves.
{More analysis to follow.}
Black to play. No komi.
Shirae also played the 10-3 extension with
. Sugiuchi (still active at age 92, see the Sugiuchi watch thread, viewtopic.php?p=241376#p241376 ) replied with , the standard checking extension on the right, only a two space extension because of the weakness of the ogeima enclosure. Black then pincered on the left side, and the battle continued there for several moves.{More analysis to follow.}
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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EdLee
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... big wedge-extension or otherwise.-
Bill Spight
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Re:
EdLee wrote:Curious about a low-end bot's evals.
Interesting.
Since Deep Leela was trained on human play, I thought that it would agree with a human at least once. Cho-Kono (small typo in #534's date: '1907' )
My bad.
OTOH, the spell checker changed Cho's name to Cho Chicken. 
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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John Fairbairn
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Re: This 'n' that
Bill
Just as background for your splendid efforts.
I have been trying to come to terms with what I thought was something odd about facing shimaris in pro play. Like you, I think, I was brought up in go during the Takagawa era. What I learnt then was that the main direction of play from the ikken tobi shimari was along the side that makes an L shape. The reason was that this leads to a box shape rather than a tray shape. I have been increasingly puzzled lately (even before AI times) as I have noticed more and more pros favouring the other ("open") side. I cannot recall seeing anything about this in fuseki books.
This is so extreme that (from memory) of over 200 games that I have with facing ikken tobi shimaris, in only two, I think, was the centre mid-point played.
Where one kogeima shimari faces an ikken tobi shimari, the centre mid-point play was rather more common, but still close to disappeared from pro play around 2010, or even earlier.
But - big BUT - where a kogeima shimari faces another kogeima shimari, the centre mid-point is a very common play even today.
That has long baffled me. But in the light of what the bots have shown us, one vaguely possible thought has come to me: a contact play at the third-line root of the shimari seems powerful with a kogeima shimari, but less so against the ikken tobi shimari. Is that side therefore favoured for an extension from the kogeima simply to avoid that sort of contact play. I have seen nothing in print to support that, but I do recall that Yi Ch'ang-ho led a fashion for playing a very early contact play on the second line. Could it be that he was on the same lines as the bots but just didn't realise the third line was better than the second for the contact play?
Just as background for your splendid efforts.
I have been trying to come to terms with what I thought was something odd about facing shimaris in pro play. Like you, I think, I was brought up in go during the Takagawa era. What I learnt then was that the main direction of play from the ikken tobi shimari was along the side that makes an L shape. The reason was that this leads to a box shape rather than a tray shape. I have been increasingly puzzled lately (even before AI times) as I have noticed more and more pros favouring the other ("open") side. I cannot recall seeing anything about this in fuseki books.
This is so extreme that (from memory) of over 200 games that I have with facing ikken tobi shimaris, in only two, I think, was the centre mid-point played.
Where one kogeima shimari faces an ikken tobi shimari, the centre mid-point play was rather more common, but still close to disappeared from pro play around 2010, or even earlier.
But - big BUT - where a kogeima shimari faces another kogeima shimari, the centre mid-point is a very common play even today.
That has long baffled me. But in the light of what the bots have shown us, one vaguely possible thought has come to me: a contact play at the third-line root of the shimari seems powerful with a kogeima shimari, but less so against the ikken tobi shimari. Is that side therefore favoured for an extension from the kogeima simply to avoid that sort of contact play. I have seen nothing in print to support that, but I do recall that Yi Ch'ang-ho led a fashion for playing a very early contact play on the second line. Could it be that he was on the same lines as the bots but just didn't realise the third line was better than the second for the contact play?