X marks the spot

[John Fairbairn]

I also think that corners, sides, center, is flawed. My thinking is more like corners 1, corners 2, sides, and center any time. For instance, sanrensei is doubtful, but suppose that the opponent invades one of the corners and you block on the side facing your other 4-4 stone. The opponent pushes and you extend to the 5-4. If the opponent now slides, the side 4-10 point now becomes good, even before another play in the adjacent corner, because of the power of the center facing 5-4 extension.

Bill: I agree about 4-10, but in my algorithm the fourth line forms part of the centre. I think even amateurs are always aware that a debate is always possible about extending on the third or fourth line. But that debate is still presented in terms of this side move or that side move. But my AI-influenced thinking is now that you should be thinking centre (4-10) or side (3-10), and that if 3-10 is better for some reason, you have probably made a mistake higher up the tree. Similarly with pincers (a leviori or a fortiori?). As someone who plays a lot of attention to words, I think there is also a strong case to distinguish between playing in the centre and playing to influence the centre.

Not entirely apropos, but I invite you to look at this early 17th century 3-stone game by Guo Bailing (White):



Moves 5 and 7 think about the centre, but so does the very AI-ish 9. It is this move, not my theories, which led Tom Koranda to bring it to my attention. But I couldn't resist looking at the final position. Look at who has control of the major diagonals (and barmkins) despite the 3-stone lightning bolt Black started with.

Incidentally, much of my recent thinking has been heavily swayed by looking at old Chinese games again. Because of the need to stress group connections in view of group tax, they had to pay more attention to centre-influencing moves, and both Tom and I have been astonished at how any AI-type moves they made. I think this is rather similar to what you are noticing about Edo no-komi games in Japan. Because White had to try that bit harder, I suspect he was putting more emphasis on influencing the centre. Again I want to stress the terminology. My choice of 'influencing' may not be the best, but I think it's important to get away from the crude idea of just 'playing' there or 'occupying' it. I am enjoying looking for ways White (or the old Chinese players) do this, and it's been quite illuminating. Here's an example (the triangle was the last move):



The game is GoGoD 1680JQXG208. The great Shi Dingan commented on it. He criticised White 91, which was at A. He basically said it was ajikeshi and White was making his own future play uninteresting, and indeed the result was that White sealed off his side of the corner, and Black got a safe enough group. Shi recommended the cap at B.

I was intrigued by that because A looked fine to me, so I put the position in Lizzie, and was not surprised to see it favoured A. I continued through the game, feeling very smug until it dawned on me what Shi was pointing out. Suddenly B made a lot of sense. I'm not good enough to know whether it really is a better move, but I could see factors that I had overlooked before. First of all, Lizzie's opinion was entirely irrelevant. With group tax this is a different game.

Second, what I noticed as the game progressed was that Black easily joined up his weak top group to a group below, and for a time was even looking at joining up three groups. At 2 points per join, that's a huge difference. B would interfere with possible connections for as many as five Black groups (or six if you consider the cut at P8). This B is a move I regard as 'influencing' the centre big time, in this case.

The third thing that dawned on me was that, having seen the Sino-Japanese character for 'aji', I was still in Japanese mode, and so was thinking in terms of tactical shenanigans to do with the Black group at the top (and that sense of aji was also why I had fancied White A - good idea to get rid of Black's aji in the corner. But this was Sino 'wei' - subtly different connotations in old Chinese: strategic 'taste' as well as 'tactical 'taste'. Shi was talking strategy and I was thinking tactics! I was playing in the centre. He was playing to influence the centre.

[Knotwilg]

I don't want to give too much away

I for one am more interested in your discovery than the tale of it - while I'm sure the tale is for many's enjoyment.

neither do I want to get drawn into spending too much time on this thread

A tough challenge!

The example is the one below, which was the first example in knotwilg's new series on Attack & Defence. I choose this simply because, when I saw it, I was surprised that he said it was hard to evaluate. It looked simple to me - there was a classic barmkin!

Have you discussed the barmkin theory before? Or is it a recent discovery?

The diagonals I am talking about - which I (?surely correctly) called "major diagonals" - run A1 to T19 and A19 to T1.

OK, we can work with that!

My program tells me that the area of interest for the next play is main the left side (the whole half), but with some secondary interest in the top left triangle (north of the A! to T19 line).

I'm left to assume that this is due to Black having played 2 stones extra in the remaining area.

It also tells me that the likely move will be on the third line or below (but does not have to be).

This I can't reengineer.

At this stage I, the human, take over. I choose promising points in the designated areas and then run the new position through the program. I can then choose the move that gives the biggest desirable change.

Change in what?

Essentially this is the figure that shows the highest preponderance of control of the entire board

How does your program measure "control of the entire board"?

but when I make my choice I impose two things on the available moves: (1) my human knowledge as an amateur go player, and (2) a preference for a move that closes gaps in areas where the opponent had a lead over moves in areas where I already have a lead - lead as defined by the program's preponderance count, of course. This preference is the result of my observation that best results seem to come from avoiding unstable equilibrium.

I would think "available moves" are either inspired by your go knowledge, or by the algorithm. Is there a first source for available moves (other than mere legal moves)?

Note carefully that I am not choosing an area and then trying to get help with the precise spot therein to play. I want the program, which surveys the entire board, to show me the area or areas to play in. This is fundamentally different from what Mizokami advocated.

So all in all, the program tells you which area to play in, then you apply go knowledge to choose the move. That I can fathom. I still don't see how the diagonals fit in though.

I ought to have added also that when there is an obvious hotspot, that takes precedence over the program, and I define the hotspots on the fly. I see no hotspot here, so I look for a move on the third line on the left side. Strictly, I should input lots of moves as per what I described just above, but I'm a great fan of common sense (aka laziness) so I would play A.

So there are exceptions to your procedure where you bypass the area algorithm and just make an obvious best move. Fair enough.
I can see how the left side comes out of your program but not how it will designate the 3rd line (and not the 4th for example). But we're repeating ourselves.

Beyond saying that it's obviously not a daft play, I'd find it hard to justify it in human terms. I could easily say that I am keeping away from thickness (Black's, above), but I could then say, well, if that's such a good idea, I can go one point further and bang up against the White 3-3 stone. It's already strong, so I don't mind strengthening it further, and I might even overconcentrate it.

Yes, this is one of the things we still haven't figured out, why in general AI prefers approaching 3-3 and not "shoulder hitting" it. Again I don't understand how your allegedly simple C# program gets to similar conclusions as AI. Why has no programmer figured that out before? Can you really not give us the simple logic behind it?

I could waffle along further in similar vein, but when it comes down to it, I'm just choosing the moves that I'm familiar with. Strangely (or otherwise?) I seem to do quite well that way, and nearly every time end up on one of Lizzie's blue spots or a second or third best spot.

Jaw dropping indeed.

One thing I do not do is a tactical search beyond a mere glance. Also, I do not factor in sente and gote. This is another thing that I perhaps ought to have mentioned before. I have come to the conclusion (on the basis both of rational thought and observations with my program) that sente and gote don't matter to a bot and probably shouldn't matter to us. That's a big and provocative statement, I know, but I'm fairly sure of it. However, I'm not going to elaborate on it here. I just toss it out as a thought.

It's a big thought. I agree a bot doesn't think of sente or gote. It does in probabilities and game results. But when interpreting those, we must stick with such concepts until we've either become bot-like or the game has been solved, leaving no room for heuristics. Neither is likely to happen. Replacing all concepts with counting arguments is not inconceivable but it's indeed baffling to read this from the biggest enthusiast I've known of Japanese Go terminology amassed through the ages. You are sure you're not impersonating a bot aficionado to make a fool out of all of us?

(...)

That said, what I noticed straightaway in the diagram above was the nicely laid out barmkin (the rough and ready enclosure around the 5-5-, 6-6, 7-7 etc points) in the northwest. Even without counting, I could see at once that Black has a strong preponderance of control over the A19/T1 diagonal, and the other diagonal is instantly visible as split 50/50. So, making the usual assumptions about pro games (e.g. that there have been no horrendous mistakes already), Black is comfortably in the lead. I have no idea by how much, but I would certainly prefer to be Black.

I have the feeling we can engineer similar positions where the same reasoning applies but the disposition of the stones is such that White is in the lead. I can't accept that all the heuristics we have developed (shape ...) have become worthless.

(...)

So, if I am not offering an algorithm, what am I offering? Just exotic food for thought. I think the new nouvelle cuisine can be "fusion" food - a blend of AI and human ingredients. But you have to be your own chef.

I take this post and the additional comments as an account of an epiphany but it strikes me as too much too soon and too easy. I'm the first to learn from what AI seems to tell us but I'm skeptical of the seemingly casual reduction to a "preponderance of control" algorithm in certain areas which comes close to AI performance.

[John Fairbairn]

I take this post and the additional comments as an account of an epiphany but it strikes me as too much too soon and too easy. I'm the first to learn from what AI seems to tell us but I'm skeptical of the seemingly casual reduction to a "preponderance of control" algorithm in certain areas which comes close to AI performance.

I won't answer your other points, because I think I have addressed them already - except your question whether it was a recent discovery. Not recent, but originally embryonic and developed over a period of some months. The C# program is the only recent bit. The references to barmkins and so on are like icing sugar, and reflect whatever is going on in my mind at the moment. Barmkins came because I had been listening to a beautiful pipe tune that was turned into a song recently by a prominent tv personality. It was about an area I used to go rock climbing in and which is full of peel towers - and cows. (Search on Rothbury Hills and Alexander Armstrong if you want to hear it, but best of all prefer the pure pipe version by Kathryn Tickell.)

It's the ideas that matter not the imagery. That's just for entertainment, which I feel is still sorely needed during lockdown.

I have made plain that I'm as surprised as anybody at the results, and also that I don't understand it (though the diagonals and barmkins were, I think, a successful attempt to get a firm footing on the crags). I have also no idea how to distil and bottle what I have learnt, but am not going to make much effort in that regard either. (But just in case, I'm keeping my topography (the 14 areas and overlaps) under wraps )

What I hope to get out of it is what I hope to get out of most of my posts: to stimulate shared ideas from other people. In the case of abstract ideas about AI, the sort of posts I have enjoyed thus far have been from Bill, and to a lesser extent from uberdude, and, er, that's about it - though I think your recent post about 'reinforcement' for shimari deserves an honourable mention. In fact, with that and your post on Attack & Defence, you can take much of the blame for me posting now!

Far from being a spoof, my present posts are more yet another desperate but vain attempt to generate lively discussion here.

[Bill Spight]

I agree a bot doesn't think of sente or gote. It does in probabilities and game results.

I beg to differ. True, as far as we can tell, the bots do not have concepts as we normally understand the term, or at least they cannot communicate them if they do. But they must have some understanding of sente and gote, or they could not play ko fights. Furthermore, as in the recent Attack and Defense problem, they often prefer to play kikashi (sente) before making a big play. OC, they don't say that's what they are doing, but that's what they do.

As for thinking in terms of probabilities and game results, well, that's how the programmers of the bots were thinking, and that is based, I suppose, on Monte Carlo Tree Search and reinforcement learning. We can't really conclude that that's how the bots are thinking, any more that we can conclude that humans are thinking in terms of neurotransmitters and spiking axons. Gödel, Escher, Bach delves into such questions.

[lightvector]

The game is GoGoD 1680JQXG208. The great Shi Dingan commented on it. He criticised White 91, which was at A. He basically said it was ajikeshi and White was making his own future play uninteresting, and indeed the result was that White sealed off his side of the corner, and Black got a safe enough group. Shi recommended the cap at B.

I was intrigued by that because A looked fine to me, so I put the position in Lizzie, and was not surprised to see it favoured A. I continued through the game, feeling very smug until it dawned on me what Shi was pointing out. Suddenly B made a lot of sense. I'm not good enough to know whether it really is a better move, but I could see factors that I had overlooked before. First of all, Lizzie's opinion was entirely irrelevant. With group tax this is a different game.

Second, what I noticed as the game progressed was that Black easily joined up his weak top group to a group below, and for a time was even looking at joining up three groups. At 2 points per join, that's a huge difference. B would interfere with possible connections for as many as five Black groups (or six if you consider the cut at P8). This B is a move I regard as 'influencing' the centre big time, in this case.

For what it's worth, KataGo *does* handle group tax, but even with group tax enabled, it prefers A by a large margin (20% winrate, many points). If I look at the followup variations suggested, it seems like the issue is that the looser B, while strategically interesting, simply loses too much locally by making it too easy for black to settle using white's corner thinness. Well, easier by bot standards at least.

Some playing around with things reveals that although it doesn't change the judgment of this move much, group tax *does* affect KataGo's strategic choices quite significantly in some positions. I started another thread here with some examples: viewtopic.php?f=15&t=17674

I agree a bot doesn't think of sente or gote. It does in probabilities and game results.

I beg to differ. True, as far as we can tell, the bots do not have concepts as we normally understand the term, or at least they cannot communicate them if they do. But they must have some understanding of sente and gote, or they could not play ko fights. Furthermore, as in the recent Attack and Defense problem, they often prefer to play kikashi (sente) before making a big play. OC, they don't say that's what they are doing, but that's what they do.

As for thinking in terms of probabilities and game results, well, that's how the programmers of the bots were thinking, and that is based, I suppsose, on Monte Carlo Tree Search and reinforcement learning. We can't really conclude that that's how the bots are thinking, any more that we can conclude that humans are thinking in terms of neurotransmitters and spiking axons. Gödel, Escher, Bach delves into such questions.

As a bot programmer, I mostly agree with Bill here.

Way back when I was initially playing with neural net move prediction (no self-play, just trying to predict pro moves), I found through some visualizations that the neural net had developed internal features that clearly corresponded to things like "ko" and "territorial control" and "incomplete borders", see here:
https://github.com/lightvector/GoNN#glo ... s-dec-2017

For "territorial control", the fascinating part was that the neural net was *not* trained to predict the outcome of the game, it was only ever shown pairs of (board position, location where the pro would move next). So in some sense, the net was not explicitly given any notion that this was a game with an actual goal, that areas could be owned or not, or that stones could live or die. Nonetheless, presumably it discovered on its own that summing up "control" of areas of the board, including correctly identifying when stones should not negate that control (due to being dead), correlated reliably with stylistic shifts in how pro players would play.

Buried somewhere in current nets, it's extremely likely there are channels or combinations of channels that activate according to or otherwise encode concepts that correspond loosely to what humans would call "sente vs gote", as well as finer judgments their relative urgency or threat potential, whether they are losing or gaining, and so on. Very likely sliced up and parameterized and blended with other concepts in ways that aren't the ways humans would, but still there nonetheless.

[John Tilley]

Some background to Mizokami and also a pointer to an article by John F in "New in Go" that might help with this thread.

I think the concept of dividing the board into areas and counting the number of stones in each to determine "local numerical superiority" was introduced by Sonoda in his book "Good Points, Bad Points" published in 2004. Sonoda divided the board into two, horizontally, vertically or diagonally. If you have more stones in a given area then attack.

https://senseis.xmp.net/?GoodPointsAndBadPointsToPlay

Mizokami's book was published in 2013 May, he did not use the diagonals to divide the board, but I believe he took Sonoda's idea and turned it into a book.

John F posted "on a slew of books" in 2016 and referred to Mizokami's book (which is how I bought it) and "All about Sonoda's proverbs".

viewtopic.php?f=57&t=13724&hilit=slew

Sonoda published "All about Sonoda's Proverbs" in 2016 May, in the second part of the book he analyses eight professional games and uses his proverbs to analyse moves at key moments, including "local numerical superiority" - but the areas he chooses are not as large as half the board - I am not sure how he chooses those areas.

There is an interesting article in GoGod's "New in Go" (Go Seigen_1.htm to Go Seigen_16.htm) where John F looks at two books and a seminar he ran with TMark back in 2002. One book is with O Rissei and the other is on games from 1998 to 2000 by Go SeiGen. Page 3 of this article shows eight areas of the board on the sides that are over looked in the mantra "corner, sides, centre" - but can have a tremendous influence on the game. On page 5 John F introduces the Go Seigen Group(GSG) - which is sitting in one of those blue areas. I think that in Sonoda's terms he would describe that group as "already alive stones" and Sonoda's proverb is "playing near already alive stones is small".

This article is in the light of this thread worth reading.

Back in 2016 John F said about Sonoda's book that "very, very happy to have found this book" - but that was before AI. Personally I like Sonoda's book and his advice on ways of looking at the board.

John Tilley

[Kirby]

If there's no algorithm, then to me, I guess it's kind of interesting to read about, but not very useful. Things are useful to me if I understand them. Without an algorithm or a way to describe what's being talked about here in concrete terms, I don't have that understanding.

Let me recommend to you the other way of getting understanding: thinking. Cook for yourself instead of devouring fast food.

I *am* thinking. That's why I'm asking questions about the vague idea that you proposed. I asked about an algorithm, because you're the one proposing that you've made some sort of discovery. Just asking what it is. If there's nothing there that you'd like to discuss in concrete, understandable terms... that's cool, I guess.

[Harleqin]

Some incomplete thoughts:

“Corner, side, centre” has been proposed as outdated now. I think that it might be replaced by “gradually increasing corner areas”—up to 10×10….

Starting from there and looking at the other extreme: where is the first “corner area”, the one to perceive on the empty board? Certainly not 1×1. Most likely 3×3.

So, when you play 4-4, you're basically skipping the actual corner. (Yes, that seems “known” so far.) For what? Again, known: “for the outside”. That is: for larger parts of the further “rings” around the corner.

Classically, the sides (3rd line: the line of territory; 4th line: the line of “influence”), are valued highly. What I take from John's writings about the diagonals is that this is another line that should also be considered; maybe the “line of control”?

Of course, we wouldn't usually consider extending to the centre at first. But Go Seigen would, he proposed that three diagonal hoshi (hoshi, tengen, hoshi) might be the best sanrensei, and the big triangle (nirensei plus tengen) the second best. Alas, it doesn't seem to be that simple.

Finally some anecdotal data: when playing Katago online at 5 handicap, it would respond to a high answer to kakari almost invariably with this peep:

$$B
$$ -------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . 2 . . .
$$ | . . . X . . . . .
$$ | . . . . 4 . . . .
$$ | . . . 3 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

Click Here To Show Diagram Code

[go]$$B
$$ -------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . 2 . . .
$$ | . . . X . . . . .
$$ | . . . . 4 . . . .
$$ | . . . 3 . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]

[John Fairbairn]

Classically, the sides (3rd line: the line of territory; 4th line: the line of “influence”), are valued highly. What I take from John's writings about the diagonals is that this is another line that should also be considered; maybe the “line of control”?

I have become increasingly aware that we may have become trapped into a Japanese Weltanschauung of go. I have had this feeling for decades, partly because of go-specific comments made by Go Seigen, partly through looking at old Chinese games, and partly from reading about Chinese strategy and tactics outside of go. But the feeling has recently intensified. This was driven in the first instance by trying to look at go though AI eyes (hence, in a way, this whole thread), but mostly by looking at old Chinese go again.

First, I think Chinese go has been misrepresented as "all-out fighting" or "power go". Even the Chinese have said this in the past, but I think too they are now re-evaluating this. But for us especially, who have different associations for words like "fighting". When we hear "all-out fighting" I suspect that the sort of images that swim up in most of our minds is pub brawls, riots, or bench clearances in baseball. Very, very few of us have had actual experience of "proper" fighting (I too was a post-war baby) and there our images are formed (or misformed) by Hollywood.

But if you go back to the classical era, "proper" fighting was something that was always a strongly potential part of life, and even scholarly Chinese gentlemen-officials who tended to despise the military men made sure they read and even memorised books like Sun Zi's Art of War. The Go Classic in Thirteen Chapters is even based on it.

It has always been difficult to get to grips with Japanese go vocabulary because until the 20th century there were essentially no texts. Books of games and problems, yes. Books with words, no. But it was very different on old China. We have lots of old commentaries, often quite long, and by go masters not amateur amanuenses. They say eyes are the window of the soul. Well, so are words.

It is very instructive to look at old Chinese go words. First of all they have been uncontaminated by Japanese vocabulary (unlike modern Chinese go terms). The palette is very, very different from Japan's. Not just in what is there but in what isn't there. No thickness, no moyos, no tewari, no miai - at least not expressed in the Japanese way. But some of the less obvious omissions (or near-omissions) may surprise you. "Attack" is actually quite a rare word. Instead they say an awful lot that a move is "severe". Is an AI bell tinkling already? Invasions, believe it or not, are rare. They like splitting moves - the whole development of Chinese fuseki, culminating in early/mid Qing times, can be seen as refinement of the 9-3 splitting move (in the area of a Go Seigen group incidentally ) - and they like encroachments. (Of course, invasions risk creating a separate group and nobody likes paying tax.)

But the one word that stands out is shi 势. Roughly translatable as power, it subsumes thickness and much else. So much else, that the US military has spent a fortune on trying to understand shi, which is still the basis of Chinese military strategy and political strategy - and much else! Can you imagine the Pentagon spending money on studying thickness to understand Japanese politics. Old Chinese go is real hand talk - not a pale Japanese imitation.

And Sun Zi is always there in the background. The most eye-opening moment in go for me recently was discovering Huang Longshi's Five Grounds - based of course on Sun Zi's Nine Grounds.

Now, if you look at just these two elements - shi and grounds through the prism of old Chinese go terms, you get a feel for the game that is very different from our traditional Japanese-based feel and one that, I believe, more accurately mirrors what is going on in AI go.

You need to read at least one big book to even get a tenuous feel for shi (Mott & Kim is the definitive one in English) but if I may be allowed to try to distil it in to one English word, it would be CONTROL. With some caveats - it is not just control in the sense of having your hands round the other guy's throat or other important anatomical parts but is also control in the sense of sheer overawing presence (and so, to go off at a slight tangent, this is why I keep saying that thickness with weaknesses is not thickness and that thickness is not thickness unless it functions as thickness - but function here means control rather than attacking).

Now consider this: one common name for the four starting stones of old Chinese go is "shi stones". Control stones if you will. And these stones are placed diagonally, so that each player starts with a LINE OF CONTROL, i.e. X marks the spot.

The other element of my attempt to model AI go was to map the board into overlapping areas. It seemed to work, although in a crude way. But I tried this before I discovered Huang's Five Grounds, and since then I have refined my thinking to reflect that. Think of grounds as a locale, an area where both players may be present and engaged in various ways (as defined by 'control' - battle areas, if you like). These grounds shift as stones are added, which makes them way, way beyond my ability to program, but one thing I noticed, by reading the old commentaries and analysing the words, is that time is an absolutely crucial element. Not in the ultra-crude way of sente and gote but in the wider (and subsuming) sense of initiative, in which you can play a gote move to keep the initiative (the Japanese gote no sente, of course, but bigger than that). The number of comments in old Chinese texts that describe moves as well timed or the in right order struck me as far higher than anything in Japanese texts. I think we tend to think of timing simply in terms of technique or tewari. In reality, as the old Chinese commentaries show, timing is about keeping CONTROL.

I have also been struck (as I was decades ago but didn't understand it then) by how often the old Chinese commentaries have recourse to terms such as 细，which gets translated in tone-deaf ways such as "meticulous", and 落得, also rendered in tonally deaf ways such as "is advantageous". I believe the go sense of 细 is better understood as "tactically precise", and once you get in that mindset you realise that this too is about keeping CONTROL (and, mutatis mutandis, defining the shifting grounds). 落得 seems to have made an impression too on the old Japanese players. They rendered it as 打得, both versions meaning literally "can play" but the reference is to the (early) timing of forcing plays. Rather than the move being "advantageous" it is a no-loss move, which has very different connotations. And, in my new view of go, what that translates into is a way of defining GROUNDS. More bars tinkling on the AI Glockenspiel?

So, trying to put all that into a broken nutshell, I think a new theory of go in the AI era should look back at the old Chinese past (and/or Edo go, especially Dosaku, in Japan - but China mainly because of the huge volume of commentaries) and should emphasise primarily CONTROL and GROUNDS, with a strong secondary emphasis on severity, precision and timing as a way of keeping control and defining grounds.

And if you do revisit old Chinese games, think of them as battles and not fights. Even changing just one word changes the word associations and thus the perceptions. They do have highly developed strategy (as well as impeccable tactics!).

[Bill Spight]

Some time back I proposed that one of the oldest concepts in weiqi was that of the base, in particular that of the two space extension on the 3d line, the prime example being 8-11 (or equivalently, 9-12) base on the side. The concept may have been quite specific. Implicit in the 9-3 play is a notion of miai, in the sense of the ability to make a base on either side. There may also have been a notion of sente. But, as John points out, none of these concepts seem to have been articulated in words. Anyway, below are some ancient games from the GoGoD collection where I have made a few comments. BTW, it would be interesting to review some ancient games with AI, eh?

[Ferran]

Maybe it's a silly question, but... if we started using the old 4-4 pre-placements... how many 3-3 early invasions would we get? Because every era has its favourite joseki, but I'm really getting tired of these ones.

Take care.

[Bill Spight]

Maybe it's a silly question, but... if we started using the old 4-4 pre-placements... how many 3-3 early invasions would we get? Because every era has its favourite joseki, but I'm really getting tired of these ones.

Well, if you are Black you could play something like this.

$$Bcm5 Only one invasion
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . 4 . . . . . . . 5 . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 3 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . 6 . . . . . . . . . . 1 . . . . . |
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------

Click Here To Show Diagram Code

[go]$$Bcm5 Only one invasion
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$$ | . . . . . 4 . . . . . . . 5 . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
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$$ | . . 3 . . . . . . . . . . . . . . . . |
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$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . 6 . . . . . . . . . . 1 . . . . . |
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Here is a pre-AI game record that starts off with the traditional setup. The SGF file is a trimmed and edited version of one of the Elf GoGoD commentaries. I added estimates of the percentage loss of plays. Any play with a loss of less than 3% should be playable. A play with a loss of more than 5% is probably an error. IMHO. It should offer you some ideas for alternate plays and joseki.

Edit: Oh, yes. In the comments the decimal fraction is Elf's estimated winrate for Black. The second line shows the number of rollouts for that estimate.