Yesterday's rule dispute in Korea

[Pio2001]

I think that the main thing that will meet player's opposition is the fact that the button is supposed to be worth 0.5 points, but when you count the game filling territory with the prisoners, the button is actually worth zero !

I'm not sure what you mean by that.

I am talking about your description of AGA territory button go in page 3 of this discussion.
The introduction to button go in general says that there is a token, called the "button", that is worth 0.5 points. Which means that it is interesting to take it once there are no more valuable plays available.
But in the rules, the one taking the button does not get 0.5 points. Instead, he -sometimes- gets the right not to hand a pass stone when he passes.

That's one artificial way (the button) to trigger another artificial way (the pass stone) to get some points.
I can already see the player's reaction : "Come on, we're playing go, not poker ! The points are on the board !"

Actually, it's the other way around. The rule about who passes last is one way to implement the button.

That is what Jaeup has just talked about.
Your text was different. In your version, one has both to be careful about taking the button and also to be careful about who passes last.

Another way is to say that Black pays one point to make the first pass, but White does not (by the WMSG rules).

One point of area or one point of territory ? Sorry I don't know the WMSG rule.

The original idea of pass stones was to implement area scoring, it was not that area scoring was a way to trigger pass stones.

Right, this is pure area scoring. Pass stones are just here as a way of counting faster. They don't change the rule.

Here lies the main difficulty for the adoption of button go, in my opinion : the button changes the rules. The pass stones did not.
It even changes the rules in a way that is very difficult to understand. It looks like territory scoring at first sight, but not completely. At least not as the Japanese rule defines "territory".

[moha]

The first change to go to the button go is the adoption of the pass stone in the existing area scoring rule.

About this we have actual data: narrow support so far as mentioned.

The second change is the adoption of the rule that "the opponent of the second passer makes the lass pass." If they already accepted the pass stone, I don't think it is such an enormous barrier. (Of course Korean/Japanese players will welcome it, and the Chinese player's reaction is the only issue.)

Korean/Japanese players would probably prefer this over being forced to play in Chinese rules, but I don't see them accepting this over their existing game (little benefit).

For Chinese players I'd expect two problems. First is the general inertia against any rule change (which is a GOOD THING in my opinion). The second is the "delay winning last ko" trick. This significantly changes the game and strategy in not-so-rare positions, creating a third game besides Japanese/Korean and Chinese. I wonder what Chinese pros would think about this ruling. (And this is why something along the lines of "fewer stones played wins ties" seems interesting.)

[RobertJasiek]

$$ Capture game
$$ ----------
$$ | . O X X X |
$$ | O O O X . |
$$ | O O X X X |
$$ | 1 O O X . |
$$ | 2 O X X X |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | . O X X X |
$$ | O O O X . |
$$ | O O X X X |
$$ | 1 O O X . |
$$ | 2 O X X X |
$$ -----------[/go]

"We know that White can play on the left side to a position worth 0. If Black plays on the left side White can capture the Black stone and win, so Black has no play there. We count the left side as 1 pt. for White. By convention we write values from Black's point of view, so we score the left side as -1."

If B starts, we get {|0}. If W starts, we get {|} = 0. Is {|0} = -1? So is the initial left side {0|-1}? What number is this?

$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

"Continuing in this vein, we can score the right side as +3"

Explain for CGT calculations for the variations, please! It is not obvious.

[Bill Spight]

I think that the main thing that will meet player's opposition is the fact that the button is supposed to be worth 0.5 points, but when you count the game filling territory with the prisoners, the button is actually worth zero !

I'm not sure what you mean by that.

I am talking about your description of AGA territory button go in page 3 of this discussion.
The introduction to button go in general says that there is a token, called the "button", that is worth 0.5 points. Which means that it is interesting to take it once there are no more valuable plays available.

That is a description of the button under area scoring, not territory scoring.

But in the rules, the one taking the button does not get 0.5 points. Instead, he -sometimes- gets the right not to hand a pass stone when he passes.

You will note that I separated the two sets of rules, depending on the scoring method. The easiest way to implement the button under areas scoring is to use a token worth ½ point. AGA territory scoring uses pass stones, so that is not the easiest way in that case. You are complaining about the inconsistency between the two, which will affect neither the play nor strategy.

I can already see the player's reaction : "Come on, we're playing go, not poker ! The points are on the board !"

Players who feel that way can use the territory scoring method.

Actually, it's the other way around. The rule about who passes last is one way to implement the button.

That is what Jaeup has just talked about.
Your text was different. In your version, one has both to be careful about taking the button and also to be careful about who passes last.

People have objected to the rule that White must sometimes make a third, obligatory pass. I wrote the text to get over the objection of sometimes having an obligatory pass. Jaeup requires an obligatory pass, not by White, but by the player who did not take the button. Both in his implementation and mine you have to be careful about taking the button and about who passes last.

Another way is to say that Black pays one point to make the first pass, but White does not (by the WMSG rules).

One point of area or one point of territory ? Sorry I don't know the WMSG rule.

From an earlier note in this thread.

The 2008 World Mind Sports Games in Beijing implemented Button Go without calling it that. They used area counting, but implemented the button in this way.

There are two types of compensations. The first type depends on who passes first in the game. If White passes first, Black's score is reduced by 1. If Black passes first, no such compensation is given.
The second type of compensation aims to balance the advantage enjoyed by the player who makes the first play. To ensure a fair game, the Black player is asked to deduct an amount from his total points, traditionally known as the komi (tie-xian in Chinese). The amount of komi in this tournament is set to be 6.5 points.

Emphasis mine.

In the tournament they used the Ing fill-in method of counting.

The original idea of pass stones was to implement area scoring, it was not that area scoring was a way to trigger pass stones.

Right, this is pure area scoring. Pass stones are just here as a way of counting faster. They don't change the rule.

Here lies the main difficulty for the adoption of button go, in my opinion : the button changes the rules. The pass stones did not.

Actually, they did change the rules. Before their adoption the AGA played by Japanese scoring. And even today, most AGA players use some form of Japanese scoring in their regular online games.

It even changes the rules in a way that is very difficult to understand. It looks like territory scoring at first sight, but not completely. At least not as the Japanese rule defines "territory".

No, they are not. The main difference with Japanese rules is that points are counted for territory in seki.

[Pio2001]

There was an interesting game in a Women's professional league game. (Youngjoo Lee (W) vs Minjin Lee (B))

It is in the third figure of the following article.
http://baduk.hangame.com/news.nhn?gseq= ... earchtext=

I've yet to see the on-air commentary, so I do not know how the referee explained it.
Anyway, the conclusion seems to be correct in the current Korean ruleset. Also, the conclusion is the same in the current Japanese ruleset. In both cases, White can find a hypothetical play to capture all Black stones.

White does not need to make a further play at the upper left corner, and that ended the game with W + 0.5 win.

Hello,
Going back to the initial topic : you say that the conclusion is the same under the current japanese ruleset.

How can it be ? I was under the impression that under japanese rules, if the only thing left on the board is an unfinished ko, the intersection that is inside is not a point of territory (because of the unwritten rule that says that if we lift ko bans and give the sente to the opponent, the ko may be recaptured, therefore one of the stones around the empty intersection is dead).
Why is it different in this game ? According to the same reasoning, the white stone A16 should be dead, therefore the intersection A15 is dame, therefore White has no territory in A13 until she fills A15.

[Bill Spight]

The second is the "delay winning last ko" trick. This significantly changes the game and strategy in not-so-rare positions, creating a third game besides Japanese/Korean and Chinese.

I don't think that it significantly changes the strategy. OC, sometimes it does, for particular situations. But the strategy of delaying the winning of a ko to gain one or more points is well known by strong players. If the player who can win a ko is called the komaster, the player who can profitably delay winning a ko is the komonster. Komonster strategy is not a new idea.

[Bill Spight]

$$ Capture game
$$ ----------
$$ | . O X X X |
$$ | O O O X . |
$$ | O O X X X |
$$ | 1 O O X . |
$$ | 2 O X X X |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | . O X X X |
$$ | O O O X . |
$$ | O O X X X |
$$ | 1 O O X . |
$$ | 2 O X X X |
$$ -----------[/go]

"We know that White can play on the left side to a position worth 0. If Black plays on the left side White can capture the Black stone and win, so Black has no play there. We count the left side as 1 pt. for White. By convention we write values from Black's point of view, so we score the left side as -1."

If B starts, we get {|0}. If W starts, we get {|} = 0. Is {|0} = -1? So is the initial left side {0|-1}? What number is this?

$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

"Continuing in this vein, we can score the right side as +3"

Explain for CGT calculations for the variations, please! It is not obvious.

As you indicate, in CGT terms {0|} = 1. Then {1|} = 2, and {2|} = 3.

But we do not have to ask beginners to learn CGT to score the Capture Game.

$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ -----------[/go]

In this position both right and left sides are worth 0, since one player cannot play there and the other one cannot afford to play there. In each case we can count the territory as 2 pts. minus the group tax = 0.

$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ -----------[/go]

In this case we can count the left side as 0 and the right side as +1. So Black wins, no matter who plays first, as we can verify.

$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

In this case we can count the left side as -1 and the right side as +1. The total score is 0, so whoever plays first loses, as we can verify.

$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

In this case we can count the left side as -1 and the right side as +2. The total score is +1, so Black wins, no matter who plays first, as we can verify.

$$ Capture game
$$ ----------
$$ | . O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | . O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

In this case we can count the left side as -2 and the right side as +2. The total score is 0, so whoever plays first loses, as we can verify.

$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

Finally, in this case we can count the left side as -2 and the right side as +3. The total score is +1, so Black wins, no matter who plays first, as we can verify.

[Pio2001]

People have objected to the rule that White must sometimes make a third, obligatory pass. I wrote the text to get over the objection of sometimes having an obligatory pass. Jaeup requires an obligatory pass, not by White, but by the player who did not take the button. Both in his implementation and mine you have to be careful about taking the button and about who passes last.

Sorry, I was talking about Jaeup's implmentation in the message #102 of this discussion. It does not use a physical button:

A player may pass by handing the opponent one stone (called a pass stone) instead of playing a stone on the board. A pass is always legal. Pass stones are added to the opponent's prisoners. The opponent of the player who first passed must make the last move.

The 2008 World Mind Sports Games in Beijing implemented Button Go without calling it that. They used area counting, but implemented the button in this way.

There are two types of compensations. The first type depends on who passes first in the game. If White passes first, Black's score is reduced by 1. If Black passes first, no such compensation is given.
The second type of compensation aims to balance the advantage enjoyed by the player who makes the first play. To ensure a fair game, the Black player is asked to deduct an amount from his total points, traditionally known as the komi (tie-xian in Chinese). The amount of komi in this tournament is set to be 6.5 points.

Emphasis mine.

Thank you for the reminder.
I can see in my little sgf file that it reproduces the area button go results with komi = 7.

[Bill Spight]

People have objected to the rule that White must sometimes make a third, obligatory pass. I wrote the text to get over the objection of sometimes having an obligatory pass. Jaeup requires an obligatory pass, not by White, but by the player who did not take the button. Both in his implementation and mine you have to be careful about taking the button and about who passes last.

Sorry, I was talking about Jaeup's implmentation in the message #102 of this discussion. It does not use a physical button:

A player may pass by handing the opponent one stone (called a pass stone) instead of playing a stone on the board. A pass is always legal. Pass stones are added to the opponent's prisoners. The opponent of the player who first passed must make the last move.

I was talking about that, too. There is the obligatory pass.

[RobertJasiek]

$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

In this case we can count the left side as -1 and the right side as +2. The total score is +1, so Black wins, no matter who plays first, as we can verify.

$$ Capture game
$$ ----------
$$ | . O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | . O X X X |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

In this case we can count the left side as -2 and the right side as +2. The total score is 0, so whoever plays first loses, as we can verify.

$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

Finally, in this case we can count the left side as -2 and the right side as +3. The total score is +1, so Black wins, no matter who plays first, as we can verify.

I guess we CAN verify, but we do HAVE TO verify because we do not have a theorem for territory regions of arbitrary shape and allowing the defender to control by part of a two-eye-formation regardless of the starting player and regardless of the players' choices. Therefore, we must analyse all variations. Everything else is nothing but unproved conjectures.

No-pass-go is not an application of the theorem of numbers of dead stones removals / live stones played.

[Bill Spight]

No-pass-go is not an application of the theorem of numbers of dead stones removals / live stones played.

I have addressed this point, both here and on SL. Of the different forms of no pass go, it is no pass go with prisoner return that equates returning a prisoner with playing inside territory. To put it another way, different forms of no pass go have different concepts of territory (unless they do not have one).

$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | . O X X . |
$$ | . O O X . |
$$ | O O X X . |
$$ | . O O X . |
$$ | . O X X . |
$$ -----------[/go]

Finally, in this case we can count the left side as -2 and the right side as +3. The total score is +1, so Black wins, no matter who plays first, as we can verify.

I guess we CAN verify, but we do HAVE TO verify because we do not have a theorem for territory regions of arbitrary shape and allowing the defender to control by part of a two-eye-formation regardless of the starting player and regardless of the players' choices. Therefore, we must analyse all variations. Everything else is nothing but unproved conjectures.

Well, we do not ask beginners to prove theorems. But they can quickly learn these values. In addition:

$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | . O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ -----------

Click Here To Show Diagram Code

[go]$$ Capture game
$$ ----------
$$ | O O X X X |
$$ | . O O X . |
$$ | . O X X X |
$$ | . O O X . |
$$ | O O X X X |
$$ -----------[/go]

A beginner friend of mine realized, without being told, that Black to play can win this game. I could have taught him that the left side is equivalent to a dame, but did not bother. I praised him for finding the seki.

So, yes, the isolated 3 point eye is worth a dame. But that does not alter the fact that the No Pass Capture Game is a game of territory, albeit a form of territory that is different from that of regular go.

[RobertJasiek]

I realise that I do not know: what is the Capture Game?

$$Wcm16 No Pass Baduk
$$ ----------
$$ | . O X X . |
$$ | 4 O O X 2 |
$$ | 5 O X X 1 |
$$ | 6 O O X 3 |
$$ | . O X X . |
$$ -----------

Click Here To Show Diagram Code

[go]$$Wcm16 No Pass Baduk
$$ ----------
$$ | . O X X . |
$$ | 4 O O X 2 |
$$ | 5 O X X 1 |
$$ | 6 O O X 3 |
$$ | . O X X . |
$$ -----------[/go]

Why is the lower right eye worth 2 points?

[RobertJasiek]

$$ Black first
$$ -------------
$$ . O X 2 O X .
$$ . O X 1 O X .
$$ . O X X O X .
$$ . O O O X X .
$$ . . . . . . .

Click Here To Show Diagram Code

[go]$$ Black first
$$ -------------
$$ . O X 2 O X .
$$ . O X 1 O X .
$$ . O X X O X .
$$ . O O O X X .
$$ . . . . . . .[/go]

"If Black plays :b1:, White takes with :w2:, for a score of -10. (I.e., 10 points for White. By convention we take Black's point of view.)

Go Diagram
White first
Click Here To Hide Diagram Code

$$W White first
$$ -------------
$$ . O X 2 O X .
$$ . O X 1 O X .
$$ . O X X O X .
$$ . O O O X X .
$$ . . . . . . .

Click Here To Show Diagram Code

[go]$$W White first
$$ -------------
$$ . O X 2 O X .
$$ . O X 1 O X .
$$ . O X X O X .
$$ . O O O X X .
$$ . . . . . . .[/go]

If White plays :w1:, Black takes with :b2:, for a score of +8. "

Again, you claim but do not verify scores.

[RobertJasiek]

What is Bill Frazor's fractional territory position and your evaluation of it?

[Bill Spight]

$$ Black first
$$ -------------
$$ . O X 2 O X .
$$ . O X 1 O X .
$$ . O X X O X .
$$ . O O O X X .
$$ . . . . . . .

Click Here To Show Diagram Code

[go]$$ Black first
$$ -------------
$$ . O X 2 O X .
$$ . O X 1 O X .
$$ . O X X O X .
$$ . O O O X X .
$$ . . . . . . .[/go]

"If Black plays , White takes with , for a score of -10. (I.e., 10 points for White. By convention we take Black's point of view.)

Go Diagram
White first
Click Here To Hide Diagram Code

$$W White first
$$ -------------
$$ . O X 2 O X .
$$ . O X 1 O X .
$$ . O X X O X .
$$ . O O O X X .
$$ . . . . . . .

Click Here To Show Diagram Code

[go]$$W White first
$$ -------------
$$ . O X 2 O X .
$$ . O X 1 O X .
$$ . O X X O X .
$$ . O O O X X .
$$ . . . . . . .[/go]

If White plays , Black takes with , for a score of +8. "

Again, you claim but do not verify scores.

My audience is one of experienced players.