Life In 19x19

This is stimulated by the disagreement in the thread on Game 4 of the Mlily match between Gu Li and Yi Se-tol, in which amateurs appear to look askance at Yi's positional judgement whereas pros seem to think his play was fine.



As I read it, in summary, Robert was unequivocal that Yi's play was bad and in the absence of precise count-based explanations from the pros, he claims his method is the best way to judge the position. Other amateurs say "we haven't a clue why, but if the pros say it's OK it must be OK."

I lean towards the latter camp, but I also anyway oppose rather strongly the idea that in the present state of knowledge the essence of early go positions can be usefully captured by numbers. To me it's still like trying to evaluate a painting by Rembrandt by saying he used 12 colours and 75% of his brush strokes were diagonals.

However, it is incumbent upon us all to have open minds, and I would like to invite Robert to give his evaluation of the position above (Black to play, no komi).

I chose it because I think it demonstrates quite well the aspects that have come up in the discussion. There is some thickness and clearly defined territory, and the final areas are fairly well adumbrated already (I say this on the basis of knowing the final position) but several of the positions are hard to define as thick or thin and even the boundary lines not in the centre are hard to pin down. In other words, there is still quite a lot of territory to play for.

Also, I have the pros' non-numerical assessments (they seem to agree), and in that connection there is a item of assessment that is typical of pros and not amateurs which was alluded to in the other thread and which will apply here if you also wish to guess Black's next move - which is after all the point of the evaluation.

So, Robert, here is a chance to convince us without (I assume) you knowing how this game continued and ended. Fortunately you would be the last person I know to look it up before answering.

I hasten to add that I myself feel rather at sea in this sort of position, and so would grasp at any means of giving a compass bearing.

(I have not said that Yi's play in general was bad. I do not claim that numerical territory and influence counting is my method, but that it is an important part of my method. Every judgement method should also have numerical information; this, however, does not imply that my method of positional judgement is the best, because other aspects of my positional judgement can still be good or bad. When different methods are bad at different aspects, one cannot say in general that one method is better than another; one can only say that the judgement of some aspects of a particular method is better than the judgement on these aspects in other methods.)

I download the SGF and study it a bit to see if I can provide a judgement within reasonable time or whether I would need more free time than I can currently invest.

Since the SGFs are not shown properly here, you need to download them and view them in your own SGF editor.

Very nice to see an illustration of your principles in action, Robert, and despite the fact that you may have come to a different conclusion as the pros (you see it as an even board whereas the pros apparently see one party ahead) I doubt many others here could give such a well backed up opinion. Also impressive that you did the analysis and made the diagrams so quickly.

daal wrote:...despite the fact that you may have come to a different conclusion as the pros (you see it as an even board whereas the pros apparently see one party ahead)...

John never stated what the professional consensus was, so it's a bit presumptuous to automatically assume that Robert's differs from that consensus.

daal wrote:Also impressive that you did the analysis and made the diagrams so quickly.

5 minutes thinking plus 64 minutes editing:)

skydyr wrote:

daal wrote:...despite the fact that you may have come to a different conclusion as the pros (you see it as an even board whereas the pros apparently see one party ahead)...

John never stated what the professional consensus was, so it's a bit presumptuous to automatically assume that Robert's differs from that consensus.

Although it is not explicit, "Also, I have the pros' non-numerical assessments (they seem to agree)," suggests to me that the pros saw one side as having an advantage, whereas Robert writes: "In this rough description, the position (with Black's turn) is fair." Please also note my use of the word "may." I hope I wasn't being presumptuous.

daal wrote:...despite the fact that you may have come to a different conclusion...

Hi daal, I was also going to point out your "may," but you ninja'd to it. Also, I re-read it, and I wonder if the wording could be improved on? Because I got a similar feeling as the usage "You may have won this time, but..." Maybe I'm totally confused.
(How about something like: "Whether or not you came to the same consensus as the pros, ...") As Robert mentioned, so much in editing.

daal wrote:"Also, I have the pros' non-numerical assessments (they seem to agree),"

I read John's wording to mean at least 3 possibilities:
- the pros agreed one side was ahead;
- the pros agreed the game was even;
- the pros agreed the situation was very unclear (difficult to say who's ahead).

What suggested to you it was the first case?
John just said they seem to agree, but he didn't specify on what.
Or did he?

EdLee wrote:

daal wrote:...despite the fact that you may have come to a different conclusion...

Hi daal, I was also going to point out your "may," but you ninja'd to it. Also, I re-read it, and I wonder if the wording could be improved on? Because I got a similar feeling as the usage "You may have won this time, but..." Maybe I'm totally confused.
(How about something like: "Whether or not you came to the same consensus as the pros, ...") As Robert mentioned, so much in editing.

daal wrote:"Also, I have the pros' non-numerical assessments (they seem to agree),"

I read John's wording to mean at least 3 possibilities:
- the pros agreed one side was ahead;
- the pros agreed the game was even;
- the pros agreed the situation was very unclear (difficult to say who's ahead).

What suggested to you it was the first case?
John just said they seem to agree, but he didn't specify on what.
Or did he?

John Fairbairn wrote:This is stimulated by the disagreement in the thread on Game 4 of the Mlily match between Gu Li and Yi Se-tol, in which amateurs appear to look askance at Yi's positional judgement whereas pros seem to think his play was fine.

Tchan, I didn't follow Game 4. I didn't look at that game. I didn't know whether the board in this thread was from Game 4, or another, completely unrelated game.
No player info in the SGF in this thread.
I still haven't looked at Game 4, and I don't know who won, or what happened in that game.
I read this as a stand-alone, self-contained new thread.

I thought John picked a different game for this exercise.
It could be from Game 4; maybe I missed something in this thread that explained it is from Game 4.

Also, even if it's from Game 4, it could be from a different moment in the game,
than what was discussed in the other thread. I thought that's part of the point of this exercise: to examine a new board position that hasn't been discussed in that thread.

I read John's introduction, including the part you highlighted. It does not specify whether anything that follows would be from Game 4.

John Fairbairn wrote:This is stimulated by the disagreement in the thread on Game 4 of the Mlily match between Gu Li and Yi Se-tol, in which amateurs appear to look askance at Yi's positional judgement whereas pros seem to think his play was fine.



As I read it, in summary, Robert was unequivocal that Yi's play was bad and in the absence of precise count-based explanations from the pros, he claims his method is the best way to judge the position. Other amateurs say "we haven't a clue why, but if the pros say it's OK it must be OK."

I lean towards the latter camp, but I also anyway oppose rather strongly the idea that in the present state of knowledge the essence of early go positions can be usefully captured by numbers. To me it's still like trying to evaluate a painting by Rembrandt by saying he used 12 colours and 75% of his brush strokes were diagonals.

Well, I am also one who thinks that Gu Li was in the lead after . If I am sticking to my guns it is mainly because, by comparison with other amateur dans, I tend to evaluate outside influence more highly. So if even I think that White's thickness is not sufficient compensation for Black's territory, maybe it is not. To be sure, the position is playable for White, but that is not the same as equal.

I certainly do not think that the essence of any go position before it is scored can be captured by a number. However, in a funny way the value of early go positions can be reasonably estimated. For instance, I think that the value after an initial Black play on a 4-4 point is around 14 points. Not only does the value of komi suggest that, I have a method of calculation that gives that figure.

However, it is incumbent upon us all to have open minds, and I would like to invite Robert to give his evaluation of the position above (Black to play, no komi).

I chose it because I think it demonstrates quite well the aspects that have come up in the discussion. There is some thickness and clearly defined territory, and the final areas are fairly well adumbrated already (I say this on the basis of knowing the final position) but several of the positions are hard to define as thick or thin and even the boundary lines not in the centre are hard to pin down. In other words, there is still quite a lot of territory to play for.

Also, I have the pros' non-numerical assessments (they seem to agree), and in that connection there is a item of assessment that is typical of pros and not amateurs which was alluded to in the other thread and which will apply here if you also wish to guess Black's next move - which is after all the point of the evaluation.

{snip}

I hasten to add that I myself feel rather at sea in this sort of position, and so would grasp at any means of giving a compass bearing.

This position is not a good one for my methods. In a way, it is too late in the game. That is because I do not have a good way to assess the strength or weakness of groups. Early in the game that is not so much a problem. In this position, though, the White group on the bottom side is weak, and Black can mount a sustained attack.

If the group were immortal, so that Black had no threat against it, now or later, then my guess is that White would be around 18 points ahead. But plainly it is not. If it were completely dead, so that White could not even make any territory by threatening to save it, my guess is that Black would be around 24 points ahead. That is a huge difference. (Earlier in the game you are not likely to get such huge differences. )

Shall we think of the group as half dead? No. That would mean that Black to play could kill it. Maybe a better guess is that it is 1/3 dead. In that case we could estimate White as being around 4 points ahead on the board. But there is a very large uncertainty in that estimate.

What about the value of Black's sente? Normally, in a quiescent position at this stage of the game it would be worth somewhat less than full komi, around 4 or 5 points. That would make the game about even. But if White runs into the center, he would be running into Black's sphere of influence. Black will have a strong attack. Sente might even be worth around 10 points. Again, there is a great deal of uncertainty.

So maybe Black is around 5 or more points ahead in the game, give or take many points. (White is ahead on the board, but Black's sente puts Black ahead in the game.)

EdLee wrote:Tchan, I didn't follow Game 4. I didn't look at that game. I didn't know whether the board in this thread was from Game 4, or another, completely unrelated game.
No player info in the SGF in this thread.
I still haven't looked at Game 4, and I don't know who won, or what happened in that game.
I read this as a stand-alone, self-contained new thread.

I thought John picked a different game for this exercise.
It could be from Game 4; maybe I missed something in this thread that explained it is from Game 4.

Also, even if it's from Game 4, it could be from a different moment in the game,
than what was discussed in the other thread. I thought that's part of the point of this exercise: to examine a new board position that hasn't been discussed in that thread.

I read John's introduction, including the part you highlighted. It does not specify whether anything that follows would be from Game 4.

Ed, I haven't read the other thread either and I still read this as meaning that it's from game 4. I have no idea whether it's a different moment in the game from that which you think it is from. So I just think of this as a new thread as much as you do. BUT unlike yourself, I do think that it's about a moment in Game 4.

JF in his first sentence mentions Game 4 then he talks about Robert being unequivocal that Yi's play was bad (which later on RF tells us he hadn't said so). Then he later talks about "the pros' non-numerical assessments (they seem to agree)".

So from this I gather:
Something about game 4
Something about Yi Sedol
Something about pro's opinion on Yi's play being fine

If JF does not reference any other game for the position he chose, why would you think that he had picked a position from a different game? Would a different game actually be more useful to see the value of RJ's methods compared with Yi Sedol's positional judgement in a particular moment of Game 4?

tchan001 wrote:

EdLee wrote:Tchan, I didn't follow Game 4. I didn't look at that game. I didn't know whether the board in this thread was from Game 4, or another, completely unrelated game.
No player info in the SGF in this thread.
I still haven't looked at Game 4, and I don't know who won, or what happened in that game.
I read this as a stand-alone, self-contained new thread.

I thought John picked a different game for this exercise.
It could be from Game 4; maybe I missed something in this thread that explained it is from Game 4.

Also, even if it's from Game 4, it could be from a different moment in the game,
than what was discussed in the other thread. I thought that's part of the point of this exercise: to examine a new board position that hasn't been discussed in that thread.

I read John's introduction, including the part you highlighted. It does not specify whether anything that follows would be from Game 4.

Ed, I haven't read the other thread either and I still read this as meaning that it's from game 4. I have no idea whether it's a different moment in the game from that which you think it is from. So I just think of this as a new thread as much as you do. BUT unlike yourself, I do think that it's about a moment in Game 4.

JF in his first sentence mentions Game 4 then he talks about Robert being unequivocal that Yi's play was bad (which later on RF tells us he hadn't said so). Then he later talks about "the pros' non-numerical assessments (they seem to agree)".

So from this I gather:
Something about game 4
Something about Yi Sedol
Something about pro's opinion on Yi's play being fine

If JF does not reference any other game for the position he chose, why would you think that he had picked a position from a different game? Would a different game actually be more useful to see the value of RJ's methods compared with Yi Sedol's positional judgement in a particular moment of Game 4?

The position referenced in this thread does not have anything to do with game 4, apart from the fact that there is an assessment to be done, and professional opinion to compare it with.

ok, thx skydyr

EdLee wrote:I read John's wording to mean at least 3 possibilities:
- the pros agreed one side was ahead;
- the pros agreed the game was even;
- the pros agreed the situation was very unclear (difficult to say who's ahead).

What suggested to you it was the first case?

I find it hard to imagine pros agreeing on the second, and certainly not on the third possibility.