Yilun Yang: The Fundamental Principles of Go

Bill Spight · **#21**

John Fairbairn wrote:

The AIs may have "seen" something that the early pros missed about early 3-3, but it may just be that, while all these games were with komi, the earliest ones had the smaller komi of 5.5 and that influenced the human pros. Looking at all the games together for each colour invasion, with A Black 3-3 the winning rates were Black 46% and White 54%, but for White 3-3 they changed to 41% and White 59%. This discrepancy seems to match the intuition of the early pro experimenters. The difficulty for the early humans may have been is that they had a blind spot in thinking they had to play the hanetsugi - that is what AI has really taught us, not the early 3-3.

The realization that the hane-tsugi is not good is what takes the early 3-3 invasion out of the realm of the experimental and into the mainstream.

Quote:

like tengen, to take advantage of that needs extra skill that probably only AIs have. That means the real search for El Dorado is not on the fuseki shores of the game but deep in the jungles of the middle game,

Without the hane-tsugi, it seems to me that the skill required to handle the relatively weak wall is the main question. The 3-3 invasion trades territory for influence. I would say thickness, but, as you have pointed out, whether the wall can be considered thick is a real question. Until we get familiar with these patterns, it seems to me that the main burden is on the invadee.

Bill Spight · **#22**

Tami wrote:

I am quite keen to modify Yang's ranking system based on AI-derived information. That is to say, can we amateurs also use AI to construct new general principles while we wait for the pros to do it better?

Here is Yang's ranking system, paraphrased in a nutshell:

Class 1
Empty corners

Class 2
Approaches/Enclosures to assymetric corners
Mid-point of facing positions (star point/enclosure)
Starting a joseki

Class 3
Mid-point of side with fertile corner
Move that makes one side stronger and other side weaker
Approach/Enclose 4-4 or 3-3

Class 4
Completing 4-4 enclosure
Developing side with non-fertile corners
Other extensions

When you say mid-point, do you mean a play on the side near the 10-4 point? If so, I think that we have to demote those. (We also may need a fifth class.) Go Seigen had already started to demote the wariuchi back in the 1990s, and the sanrensei has generally been demoted.

Approaching or enclosing the 4-4 has already been promoted, but maybe not to the level of approaching the 3-4, as Uberdude points out. We have to add the early 3-3 invasion at the same level.

I'm not sure what you mean by starting a joseki, but if you mean playing a pincer, I observed that AlphaGo played fewer pincers than humans, and others have noticed that, as well.

Quote:

1) How would you rank a tenuki when one side plays an approach to a 4-4 point? (My Lizzie prefers to low-approach Black in the lower right when Black attempts a Kobayashi-style Fuseki)

Back in the 90s, as part of a contest by John Fairbairn, I proposed the following proverb: Tenuki is always an option. Today's bots tenuki more than humans, and I think that there is an important lesson or two there. It means that we will have to play more flexibly, that is, more lightly, and will need to develop our understanding of sabaki, aji, and furikawari.

Quote:

3) When you have low-approached a star point, how urgent or non-urgent is it to play out a joseki if the opponent answers with a knight's move?

We need to let go of the idea of finishing a joseki. As a general principle, the more stones played in an area (unless a mistake has been made), the less the value of a subsequent play. You can see this on the whole board: as the game progresses, plays generally become smaller. The same is true in local situations. That's why tenuki is always an option.

Bill Spight · **#23**

An interesting position shown by Tami:

Click Here To Show Diagram Code: [go]$$Bc Lizzie gives the highest rating (47.3%) for Black 3 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . 1 . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 2 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . 3 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

AlphaGo Teach also likes :b3:

. What top bot today doesn't?

This may be the new orthodoxy. But, as I have said, we shouldn't strain after gnats. There are other plays that AlphaGo likes almost as much, and cannot be dismissed.

Click Here To Show Diagram Code: [go]$$Bc Approach the bottom corner $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . 1 . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 2 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . 3 . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

There is little to choose between this play and the 3-3 invasion.

Click Here To Show Diagram Code: [go]$$Bc Large knight's enclosure $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . 1 . . . . . . 3 . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 2 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

This might be dubbed an inaccuracy, but I don't think we can call it a mistake. It came as a surprise to me. Not on my radar.

Click Here To Show Diagram Code: [go]$$Bc One space jump $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . 1 . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . 3 . . . . . . . . . . . . . | $$ | . . 2 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I think of this jump as a Go Seigen/AlphaGo play. It has become rather popular, hasn't it?

Perhaps we can classify all these plays as Class 2?

Next, high plays on the side, which AlphaGo rates a bit lower.

Click Here To Show Diagram Code: [go]$$Bc Class 3 plays? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . 1 . . . . . . . . . . . . . | $$ | . . . O . . . . 3 3 . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 2 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . 3 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . 3 . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Probably premature to play one of these.

Click Here To Show Diagram Code: [go]$$Bc Class 4 plays? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 3 . . . . . . . . . . . . . . . | $$ | . . . . . 1 . . . 3 . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 2 . . . . . . . . . . . . . . . . | $$ | . . . 3 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

According to AlphaGo, I think we can call these mistakes at this point, despite being joseki. I have always wondered about the slide. Why the others are demoted I'm not sure.

Vesa · **#24**

One of the rare go books translated into Finnish. Wait, perhaps the only one.

https://www.kirjavinkit.fi/arvostelut/g ... perusteet/

Cheers,
Vesa

Bill Spight · **#25**

While playing around with AlphaGo Teach to explore how to punish (if that's necessary) :b7:

in this line, I came across an interesting position at :b21:

. AlphaGo plays three different moves. The winrates differ, OC. They were calculated independently by running 10,000,000 simulations from each position. What I find interesting is that their spread is 3.2%!

Now, that does not mean that a human play with a winrate that is less than from AlphaGo's by less than 3% is not a mistake, but it indicates that there is more leeway than a lot of people suppose. Certainly we should not worry about a winrate difference of less than 1%. No point straining after gnats.

The main lesson here, I think, is that the pincers in this and similar positions are deprecated.

Also, IMO, the case for the 3-3 invasion is strengthened, even though AlphaGo chose the keima and one space jump, as well. Nothing says that AlphaGo can't make mistakes, too.

John Fairbairn · **#26**

Although I and, I think, most others are assuming the early 3-3 invasion by bots is somehow connected with, or justified by, their whole-board play much later on.

I'm beginning to wonder if that's really the case, though. After all, if a bot starts at 4-4 or 4-3 we don't assume it's seeing something around move 100 that makes these the best moves (maybe we should, but that's a huge ask...)

Now if we don't do that for 4-4 and 4-3, why should we do it for 3-3?

AlphaGo Zero played the 3-3 on move 2. Even if it did that every game, I think we'd find it hard to accept it knew there was something deep in the game that made it the best move - it would almost imply go was solved. But in fact there has only been one example of that play. So it and other bots assume in this case that other moves are better?

Yi-Tianrang played the triangled 3-3 against Deep Zen on move 3. There is now extra information on the board. But, still, other bots haven't copied this move.

In this case, the position from the book sample, when it was last White's turn, Leela Zero did indeed choose the triangled move. But it actually considered (only) three moves and the other two were 3-3 invasions on the right side. These even had a higher win rate but much inferior number of visits/rollouts. As I understand it, that means LZ is saying, "I don't like these higher scoring moves because there's too much uncertainty about them." If it's saying anything like that, that seems to imply LZ is not really seeing deep in the game. If it were a human, we would assume it is choosing these candidate moves purely on the basis of general principles or heuristics (as we would do) - in effect, choosing "local" moves. Of course it may not be doing that in reality, but if we apply reverse engineering to the process, we could easily start with that assumption. The strategic element may not be something specific deep in the middle game but simply an awareness by the bot that (say) the fourth line and third lines are not really equal (as we are taught) but the third line is significantly better.

This is all very reminiscent of the (human) debate over high approach over low approach. The popularity of the high approach has waxed and waned over the years, influenced no doubt by komi changes but possibly also by fashion. It was discussed in strategic terms but in reality it all came down to local plays. As I have indicated above, the 3-3 invasion has already been through a similar ebb and flow, and we can probably expect bots to behave in like fashion as refutations emerge. We see the same sine curve of fashion with chess openings.

gowan · **#27**

This diagram from Bill's last post above:

Click Here To Show Diagram Code: [go]$$B One space jump $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . 1 . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . 3 . . . . . . . . . . . . . | $$ | . . 2 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

reminded me of something I saw in pro games thirty or so years ago:

Click Here To Show Diagram Code: [go]$$B 19x19 diagram $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

.

I think it was attributed to Kajiwara and, depending on Black's response, might be followed by another one-space jump.

John Fairbairn · **#28**

Quote:

reminded me of something I saw in pro games thirty or so years ago:

I have no record of that precise position but the position with the five stones in the upper right quadrant has appeared in 120 games (once in 1956, and then from 1973 onwards) and what I found interesting is that (like the 3-3 invasion experiments above) it was tried by many of the very best players.

I suspect the position you recall (great memory if so!) is the one you show plus a Black stone on the upper star point, because that appeared in the Japan China Supergo in 1987 when Nie Weiping beat Takemiya with it. Go World 50 has a commentary on it (and see also Go World 60), and I think it may also have appeared in one of Yuan Zhou's books on the styles of top pros. There was a bit of psychology at play there, I suspect, because the White jump in that position had first been introduced by Takemiya in 1976. Takemiya only ever played it once more but a clutch of players tried it against him.

Bill Spight · **#29**

John Fairbairn wrote:

In this case, the position from the book sample, when it was last White's turn, Leela Zero did indeed choose the triangled move. But it actually considered (only) three moves and the other two were 3-3 invasions on the right side. These even had a higher win rate but much inferior number of visits/rollouts. As I understand it, that means LZ is saying, "I don't like these higher scoring moves because there's too much uncertainty about them." If it's saying anything like that, that seems to imply LZ is not really seeing deep in the game. If it were a human, we would assume it is choosing these candidate moves purely on the basis of general principles or heuristics (as we would do) - in effect, choosing "local" moves.

dfan may have a better and clearer explanation. But, IIUC, Leela Zero uses the Monte Carlo Tree Search strategy, even though it evaluates leaf nodes using a neural network instead of using Monte Carlo playouts. The winrate evaluations guide the tree search as it expands promising nodes. That means that nodes with high evaluations get more visits. It has been shown, I believe, that picking the play to the node with the most visits is a better strategy than picking the play to the node with the highest evaluation. That does not mean that that is the better play, if the two differ, just that it is good enough to play well. As you indicate, the program does not currently have enough information to be confident of a play with a high winrate but a low visit count.

As for seeing deeply into the game, that depends not just upon the calculation of variations of the current game, but upon the training of the evaluation algorithm (neural network). That training depends upon games that are played out, so we may say that Leela Zero's evaluation is based upon experience with a large number of similar positions. It is based upon breadth, not upon depth, per se. However, because of its breadth of experience, Leela Zero may be sensitive to a move that occurs 100 moves later than now. (Unlikely, but possible.) So it is basing its evaluations upon heuristics, but that does not mean that it is using local heuristics. Both its tree search and its training are based upon the whole board.

dfan · **#30**

In addition to Bill's post, I'll add a little precision about how Leela Zero et al are making their decisions.

They continue to look at variations, starting from the current position, until they hit some budget limitation (number of variations, or amount of time spent), then choose the move from the root position that has been visited the most.

Its tree of variations starts out with just the root position. Each variation traversal moves through the tree greedily by a heuristic to be described in the next paragraph, and ends when it reaches a node in the tree that has not been seen yet. The next traversal starts from the root again.

The heuristic is Q + U, where Q is a guess at the winrate from making this move, calculated by averaging all the winrates (generated from the value network) in the subtree starting with that move, and U is the output of the policy network (how often would it make this move based purely on intuition) multiplied by a factor that penalizes moves that already been visited a lot and rewards moves that haven't been looked at much. So, as you would expect, it is incentivized to look at moves that seem good but also incentivized to look at moves it hasn't considered yet.

So if a move has a high displayed winrate (Q) but doesn't have a lot of visits, it means that either 1) it just found the reason that it is a good move pretty recently, so the visit count is rising but isn't that high yet. or 2) it has a low U factor, which probably means that the policy (intuition) network doesn't like it much and would rather concentrate for the time being on moves that it thinks has a higher chance of panning out. These programs do not currently really have a sense of amount of uncertainty in an evaluation other than by measuring the number of variations starting from that position have been explored.

I would emphasize that this just happens to be how AlphaGo Zero works, and it's totally possible that other systems could work even better.

BlindGroup · **#31**

Tami wrote:

Here is Yang's ranking system, paraphrased in a nutshell:

Class 1
Empty corners

Class 2
Approaches/Enclosures to assymetric corners
Mid-point of facing positions (star point/enclosure)
Starting a joseki

Class 3
Mid-point of side with fertile corner
Move that makes one side stronger and other side weaker
Approach/Enclose 4-4 or 3-3

Class 4
Completing 4-4 enclosure
Developing side with non-fertile corners
Other extensions

Based on @Tami's review, I decided to buy this book, and I'm glad that I did. Definitely learning things I did not know from it.

However, I have to say that I'm not sure about his treatment of the 4-4 in the ranking system above. Specifically, the idea that extending from the 4-4 is always a higher priority than enclosing. For those who haven't read the book, he considers the lone 4-4 stone to be the equivalent of a 3-4 (or other asymmetric) enclosure for the purposes of extensions. (Obviously, they differ in their control of the corner.

) So, in the following diagram, A and B are both class 2 move for both white and black, while something like C is class 3 for both.

Click Here To Show Diagram Code: [go]$$ $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . a . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . c . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . O . . . | $$ | . . . . . . . . . b . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Certainly white b is big for white, but it's not obvious to me that it's always superior to the small knight enclosure. Not surprisingly, I can find many examples of pro games in which something like white c is played before white b. This logic also seems to lead to a rather odd conclusion in the double 4-4 opening. Here a-h are all class 2 moves and so, should be played before either player either approaches the other corner or encloses the other corner. That does not seem right at all. In fact, I just checked the database that I use, and i is the overwhelming favorite black 5 in this formation with black f being second. Leela also favors i.

Click Here To Show Diagram Code: [go]$$ $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . e . . . . . . . . . | $$ | . . . X . . . . . f . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . c d . . . . . , . . . . . h g . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . i . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . b . . . . . O . . . | $$ | . . . . . . . . . a . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Am I missing/misinterpreting something?

EdLee · **#32**

Hi BG,

Quote:

Am I missing/misinterpreting something?

Quote:

Certainly white b is big for white,

Certainly? Why certainly? In the post-AG era, I don't feel (b) is so big at all.

Bill Spight · **#33**

EdLee wrote:

Hi BG,

Quote:

Am I missing/misinterpreting something?

Quote:

Certainly white b is big for white,

Certainly? Why certainly? In the post-AG era, I don't feel (b) is so big at all.

Even before that. I vaguely recall a question back in the 90s on rec.games.go by either breakfast or sorin about "b" that suggested that he thought it was problematical. As I recall, I suggested playing a boshi against it.

Certainly it's a possible fuseki play, but maybe Class 4, eh?

Tami · **#34**

Hi Blindgroup - I'm delighted that my review helped you to decide to buy the book, and still more pleased that you're getting value out of it.

I really love this book: it's different from what I'm used to, and it's got me thinking differently too. The ability to consider issues from another viewpoint is one of the engines of growth.

However, I want to remark in relation to the position you brought up that you have to take into account Yang's writing about considering the variables of the whole-board situation, taking into account the relationships between the stones, and the need to be efficient. If you like, and if I may borrow an analogy that I think John F. came up with some years ago, it is probably wise to consider the Class Ranking system as only a set of "training wheels" (though we Britons use "stabilisers" for the same thing, so perhaps it was somebody else's analogy after all). To learn to ride a bike, stabilisers/training wheels help you to get started, but at some point you have to jettison them in order to learn to ride freely and confidently. I want to reiterate my point in the original review that a Class Two move (say) is not really so large because it is Class Two, but rather it is the relationship of the move with previously played stones that make it so large (and thus get it so high up the ranking chart). So, if you want to develop an asymmetrically placed stone, such as a 3-4, then it happens that extending a small way from it (an enclosure) happens to be a great way to do it.

Let's take this example that you cited:

Click Here To Show Diagram Code: [go]$$ $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . a . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . c . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . O . . . | $$ | . . . . . . . . . b . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Going only by the ranking system, you'd have to assign b and a to the Second Class, as they are both extensions from facing corners. But I'd be inclined to avoid it because it feels slightly slow - White's putting all her moves in the same part of the board, and if she tries to compete with Black in such a purely building-orientated way then she's going to fall behind. Also, the boushi that Bill mentions appears to be a very interesting move - it creates an ultra-deep moyo with the other Black stones. I'd think about two other suggestions:

Click Here To Show Diagram Code: [go]$$ $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . a . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . e . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . c . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . d . . . . . O . . . | $$ | . . . . . . . . . b . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

The move d is in the same region as b - but being a line higher it has more influence over the board as a whole. Also, I'd think about e - it's a move between two facing corners (I am stretching Yang's system a little bit, but not unreasonably I believe), and it asks Black some questions, i.e., it begins to challenge Black.

The thing is, I'm starting to loosen the training wheels and ride free. In my recent games, I've fallen over a few times and bumped my head or barked my knees, but I've also gained in confidence to try some really big-scale schemes out. Besides, in my practical playing experience, I find that things get "fighty" and that sometimes so much is going on that one just can't sensibly think in nice, neatly ordered categories. However, what is much more valuable for me is the confidence and toolkit for thinking about move size and efficiency that Yang's book has given me. As Leonard Cohen says "Thank God it's not that simple" - Go is much more than applying hierarchical heuristics. I don't really know how AI works - but I'm a human and need to think like one!

BlindGroup · **#35**

Tami wrote:

Hi Blindgroup - I'm delighted that my review helped you to decide to buy the book, and still more pleased that you're getting value out of it.

It was a thorough, thoughtful, and (so far as I can tell) accurate review. It also happened to be on a subject that I've been thinking about quite a bit lately, so, thank you!

Tami wrote:

However, I want to remark in relation to the position you brought up that you have to take into account Yang's writing about considering the variables of the whole-board situation, taking into account the relationships between the stones, and the need to be efficient. If you like, and if I may borrow an analogy that I think John F. came up with some years ago, it is probably wise to consider the Class Ranking system as only a set of "training wheels" (though we Britons use "stabilisers" for the same thing, so perhaps it was somebody else's analogy after all). To learn to ride a bike, stabilisers/training wheels help you to get started, but at some point you have to jettison them in order to learn to ride freely and confidently. I want to reiterate my point in the original review that a Class Two move (say) is not really so large because it is Class Two, but rather it is the relationship of the move with previously played stones that make it so large (and thus get it so high up the ranking chart). So, if you want to develop an asymmetrically placed stone, such as a 3-4, then it happens that extending a small way from it (an enclosure) happens to be a great way to do it.

Tami, I agree with everything you say here. I was actually trying to make a different point. My reference to the figure you quote was just to illustrate that both of these moves are considered class 2, even though one extends from an enclosure and one from the lone 4-4 stone. My larger concern is that, with a 4-4 stone in the corner, this system uniformly prioritizes the long extension (class 2) from the 4-4 over the two stone enclosure or the approach to another 4-4 stone (both class 3). To use your "stabilizers" example, I'd expect there to be exceptions to this depending on the board position, but after white 4, the dual 4-4 opening is entirely symmetric. This would be a situation in which I would least expect an exception to this system, but the overwhelming opinion seems to be that the 4-4 approach is preferred to the long-extension.

My impression so far is that I think this chapter does a nice job of illustrating how to think about the development of and from the asymmetric corners, but I think the 4-4 doesn't fit quite as nicely into this framework as the author would like. I will say that I have a better appreciation for the resilience of the 4-4 to the double approach and the value of the long extension from the 4-4. But I think the relative value of the long extension, approach, and enclosure of the 4-4 is more complicated than described.

Uberdude · **#36**

Blindgroup, I think the answer is fairly simple, the book is some years old and thinking of top players and even us patzers in the West has changed. Side extensions from 4-4s used to be played before knight enclosures from them (e.g. see few-decades-old Japanese games in Go World). That's what I learned 10+ years ago. Maybe top pros had already abandoned that idea back then, but at least in the 2010s early knight enclosure from 4-4s have become much more popular (this was before AlphaGo, maybe Korean-driven) and I picked this up from watching pro games and teaching from others with more up to date knowledge. It emphasises stable groups and local efficiency (side extensions can more easily end up in the wrong place). AI also tends to prefer them over side extensions, so looks like we were on the right track. If Yang wrote this book 5 years ago based on thinking at that time I expect knight enclosure from 4-4 would be higher up the list. And if he wrote it now 3-3 invasions would too (or does that count as class 2 "starting a joseki" already?).

Tami · **#37**

Uberdude wrote:

Blindgroup, I think the answer is fairly simple, the book is some years old and thinking of top players and even us patzers in the West has changed. Side extensions from 4-4s used to be played before knight enclosures from them (e.g. see few-decades-old Japanese games in Go World). That's what I learned 10+ years ago. Maybe top pros had already abandoned that idea back then, but at least in the 2010s early knight enclosure from 4-4s have become much more popular (this was before AlphaGo, maybe Korean-driven) and I picked this up from watching pro games and teaching from others with more up to date knowledge. It emphasises stable groups and local efficiency (side extensions can more easily end up in the wrong place). AI also tends to prefer them over side extensions, so looks like we were on the right track. If Yang wrote this book 5 years ago based on thinking at that time I expect knight enclosure from 4-4 would be higher up the list. And if he wrote it now 3-3 invasions would too (or does that count as class 2 "starting a joseki" already?).

Absolutely! And, any kind of ranking system is only a heuristic anyway, and obviously thinking has been evolving super-quickly recently. The fun begins when you can judge well enough to let go of it to some extent. My recent jump up of 100 Elo points in chess was simply because I did that: I started playing the position on its merits, and not just by following Nimzowitsch. Yang Yilun is my "Go Nimzowitsch" (okay, I don't think he's as odd as Nimzo, but that's not relevant); I'm already starting to find my own way. But I'm glad I've got his book

Bill Spight · **#38**

Tami wrote:

My recent jump up of 100 Elo points in chess was simply because I did that: I started playing the position on its merits, and not just by following Nimzowitsch.

Congratulations! :clap:

Quote:

Yang Yilun is my "Go Nimzowitsch" (okay, I don't think he's as odd as Nimzo, but that's not relevant);

Nimzowitsch wrote:

Why do I have to lose to this idiot?!

Gomoto · **#39**

Nimzowitsch wrote:

Why do I have to lose to this idiot?!

I want to be the Friedrich Saemisch of Go ;-)

John Fairbairn · **#40**

Hi Tami

Since you found Yang's classification style useful. I thought you may like a recommendation for a follow-up.

The book I recommend is a fairly new one (2015) and is called "Surrounding territory efficiently: the four basic points" by Kimu Sujun (ISBN 978-4-8399-5504-5).

Part of the reason for recommending it, apart from its small but neat classification, is that I mentioned earlier the not well known concept of "kakou" (surrounding) and that is obviously amply covered here (though not all the advanced aspects), but also it has a chapter on how to "mamoru" your territory, and I stressed that mamoru is quite different from ukeru - the quiet kind of move you have now learned to appreciate.

The four principles are:

1. 弱い石から囲う
2. 弱点を補強しながら囲う
3. 相手が強ければ囲わせる
4. 厚みには近寄らずに囲う

(NB kara in 1 means 'starting with' not 'from')

One of the book's great strengths is the way it shows how saying a "territory is big" is to do with much more than size or empty points. Also, each category is subdivided into sub-categories. One I especially liked was labelled 狭い地は囲わない. It sounds obvious but most amateurs do fall into this trap, I find, and as Kimu shows, it's one of the easiest things to put right (and worth a bucketful of points!)

You will, as I implied above, especially appreciate the extra chapter entitled 地を守る正しい形. One amusing pair of examples is where he shows in one that ﾄﾋﾞも甘い and in the next example that ﾄﾋが形. In other words, a gentle reminder that to play correct shape you need to think more deeply about the position and not just go to Rent-a-shape. The whole book is in this light, gentle, encouraging tone.

(Tami knows Japanese, of course. For others who know only some Japanese and have to proceed slowly with a dictionary, this book has very little text, which is nearly all limited to the subset of go's technical language. Since it covers an important topic you will not have seen before, it's worth giving it a whirl.)

Yilun Yang: The Fundamental Principles of Go

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