Moonlight life and go rules

[lightvector]

@Gerard - yep, exactly. That is why I specifically said that you need to consider some variants of such a rule depending on how you want your agreement phase or other kinds of endgame procedure to operate. Careful rules design is still necessary!

But the key essence of the matter is: with proper additional design, using such a concept, it should be reasonably possible to make superko compatible with passes lifting ko bans, and it demonstrates that the passes lifting ko bans is not fundamentally in conflict with superko for problem of sending-two-returning one cycles or other things that we wish to avoid.

I don't know if Spight still favors the concept of such a rule or has moved on to other things, but I will say that I'm pretty appreciative of a lot of such material I've seen on this forum and over the last two decades on Sensei's library, it has definitely helped shape my understanding of these things.

[Gérard TAILLE]

@Gerard - yep, exactly. That is why I specifically said that you need to consider some variants of such a rule depending on how you want your agreement phase or other kinds of endgame procedure to operate. Careful rules design is still necessary!

But the key essence of the matter is: with proper additional design, using such a concept, it should be reasonably possible to make superko compatible with passes lifting ko bans, and it demonstrates that the passes lifting ko bans is not fundamentally in conflict with superko for problem of sending-two-returning one cycles or other things that we wish to avoid.

I don't know if Spight still favors the concept of such a rule or has moved on to other things, but I will say that I'm pretty appreciative of a lot of such material I've seen on this forum and over the last two decades on Sensei's library, it has definitely helped shape my understanding of these things.

Yes, as I said this idea is quite good for me to make superko compatible with passes lifting ko bans. Do you know if it already exist a ruleset with superko, and passes lifting ko bans?

[Bill Spight]

Comparing to japonese rule this result is due to the fact that, when in AGA rule the play is resumed after two passes, all the ko bans (superko) are not lifted. Do you know if it was a real choice of the rule (in order to avoid adding some complexity to the rule)?

It is very hard for pass to lift bans under superko as this breaks the essence of superko and reinstates most problems it tried to solve (like sending2-returning1 abuse for area scoring).

This was solved years and years ago by our very own Bill Spight, no? Consider the condition "the game ends if the same player passes in a position in which that player passed before". It is easy to see how even if passes lift ko bans, that this rule still mathematically guarantees that the game is finite. It handles sending-two-returning one fine. And it even can be justified intuitively: "even when passes lift ko bans, if when I pass you have nothing better to do than cycle back the same position where I can pass yet again, clearly you have nothing you can accomplish, so the game should be over".

Depending on what you are trying to accomplish (e.g. if you want to have agreement phases or other details of game end procedure), maybe you can also consider variants. But the key essence is the condition "same player passes in a position where that player passed before".

It is a good idea, but I you say "the game ends if the same player passes in a position in which that player passed before" then you have to change the dispute article of the rule (AGA rule). Take the following basic (stupid) example:

$$B Black to play
$$ ------------
$$ | O . O O O |
$$ | . O O O O |
$$ | O O O O O |
$$ | O O O O . |
$$ | O O O O X |
$$ -------------

Click Here To Show Diagram Code

[go]$$B Black to play
$$ ------------
$$ | O . O O O |
$$ | . O O O O |
$$ | O O O O O |
$$ | O O O O . |
$$ | O O O O X |
$$ -------------[/go]

Black passes (no choice)
White passes also and designs the black stone as being dead.

Assume black does not agree! The game is resumed with black to play and black passes again and now the game ends because black has passed twice in the same situation! The black stones cannot be capture and black was right to dispute the result.

May I refer you to the Spight rules page on SL ( https://senseis.xmp.net/?SpightRules )?

At area scoring White loses nothing by capturing the Black stone. At territory scoring we may have an encore in which each pass costs one point, and each player makes the same number of plays or passes.

$$B Black to play
$$ ------------
$$ | O . O O O |
$$ | . O O O O |
$$ | O O O O O |
$$ | O O O O 2 |
$$ | O O O O X |
$$ -------------

Click Here To Show Diagram Code

[go]$$B Black to play
$$ ------------
$$ | O . O O O |
$$ | . O O O O |
$$ | O O O O O |
$$ | O O O O 2 |
$$ | O O O O X |
$$ -------------[/go]

= pass
= pass
= pass
= pass
= pass

In the encore White gets 1 net point for the extra Black pass plus 1 point for the captured stone plus 1 point for the point of territory on the 1-1 point.

[jann]

it should be reasonably possible to make superko compatible with passes lifting ko bans

Certainly, hard but possible - at the cost of extra complexity. I know Bill's approach, but I think superko in itself is already too complex for practical application, doubling on that is not too attractive (like Gérard's misunderstanding above - Bill doesn't count passes in earlier phases for stopping the current one).

it demonstrates that the passes lifting ko bans is not fundamentally in conflict with superko

There are two approaches to ko: time-wise (no immediate recapture), and position-wise (no recapture depending on the position and history).

Superko can be hacked to allow passes lifting bans, but this goes a bit against its original logic. It's not just coincidence that simply allowing passes breaks it. And with Bill's approach superko loses some of its meaning and role. Some problems that it originally tried to solve (like sending2-returning1 abose) doesn't need or use superko anymore, but play stops with the new rule.

[Gérard TAILLE]

May I refer you to the Spight rules page on SL ( https://senseis.xmp.net/?SpightRules )?

At area scoring White loses nothing by capturing the Black stone. At territory scoring we may have an encore in which each pass costs one point, and each player makes the same number of plays or passes.

$$B Black to play
$$ ------------
$$ | O . O O O |
$$ | . O O O O |
$$ | O O O O O |
$$ | O O O O 2 |
$$ | O O O O X |
$$ -------------

Click Here To Show Diagram Code

[go]$$B Black to play
$$ ------------
$$ | O . O O O |
$$ | . O O O O |
$$ | O O O O O |
$$ | O O O O 2 |
$$ | O O O O X |
$$ -------------[/go]

= pass
= pass
= pass
= pass
= pass

In the encore White gets 1 net point for the extra Black pass plus 1 point for the captured stone plus 1 point for the point of territory on the 1-1 point.

Bill, let me try to understand your proposal with an encore phase, by using the following example:

$$W White to play
$$ ------------
$$ | X X . O X O . |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X . X O O |
$$ | . O X . X X X |
$$ -------------

Click Here To Show Diagram Code

[go]$$W White to play
$$ ------------
$$ | X X . O X O . |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X . X O O |
$$ | . O X . X X X |
$$ -------------[/go]

With japonese rule it follows:

$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O 4 |
$$ | X O O O X O O |
$$ | . O X X X O 6 |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------

Click Here To Show Diagram Code

[go]$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O 4 |
$$ | X O O O X O O |
$$ | . O X X X O 6 |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------[/go]

pass
pass
with a jigo result

Can you explain what happens when the encore is used (maybe after pass but I don't know) ?

[Pio2001]

"Legal" play ALONE is not sufficient for a discussion of rule sets at the very high level that you apparently intend to do.

Utilising positions that can be reached only after several "infantile" mistakes (of both sides) cannot be the right method for qualified discussions at a "professional" level. Intending to do so disqualifies yourself.

Are you saying that we are supposed to know how to play properly before learning the rule ?

In my club, a member once began to study using books. He was a complete beginner. His first complain was that the rules of plays where not written anywhere in the book !

I know several people that tried to play go with friends, but gave up after their first game because they were unable to know who was the winner...

It is often said that go is a game with very simple rules. I nearly have a heart attack every time I read this. Go is probably the game with the most complicated rules in the world except role-playing games.

[lightvector]

"Legal" play ALONE is not sufficient for a discussion of rule sets at the very high level that you apparently intend to do.

Utilising positions that can be reached only after several "infantile" mistakes (of both sides) cannot be the right method for qualified discussions at a "professional" level. Intending to do so disqualifies yourself.

Are you saying that we are supposed to know how to play properly before learning the rule ?

In my club, a member once began to study using books. He was a complete beginner. His first complain was that the rules of plays where not written anywhere in the book !

I know several people that tried to play go with friends, but gave up after their first game because they were unable to know who was the winner...

It is often said that go is a game with very simple rules. I nearly have a heart attack every time I read this. Go is probably the game with the most complicated rules in the world except role-playing games.

As an aside (slightly off-topic for this thread), if you have the chance to influence some of these situations among your friends, one thing to try is stone scoring on a small board, such as 7x7. Take turns playing, normal capture rules, simple ko rule, and you can pass if you wish. After two passes, your score is the number of stones you have on the board. End of story.

I know many people grew up with and find "capture go" as a better teaching mechanism to introduce the game. But for cases where there *is no teacher*, where two beginners are trying to learn entirely on their own, with stone scoring Go actually really *is* a game with very simple rules, and one that is probably maximally likely for those beginners to be able to follow on their own.

[Mike Novack]

I agree with you Mike. The moves needed to reach the position are really completly stupid. No doubt about that. No dispute on my part on this point. But remember that my intention was to discuss a point in the rule by only using legal moves.
In this specific context do you agree with my point?

But by requiring allowing not just stupid, unbelievably foolish moves but also ANY LEGAL MOVE even when immediately suicidal then there is no such thing as a live group.

Consider the prototypical live group, a black group fully connected and containing exactly two separated dame. This is clearly alive even if surrounded with no external dame, yes? But NO, not by your "any legal move" definition. It would be LEGAL for black to commit self atari by playing in one of those two empty spaces.

[Bill Spight]

May I refer you to the Spight rules page on SL ( https://senseis.xmp.net/?SpightRules )?

At area scoring White loses nothing by capturing the Black stone. At territory scoring we may have an encore in which each pass costs one point, and each player makes the same number of plays or passes.

$$B Black to play
$$ ------------
$$ | O . O O O |
$$ | . O O O O |
$$ | O O O O O |
$$ | O O O O 2 |
$$ | O O O O X |
$$ -------------

Click Here To Show Diagram Code

[go]$$B Black to play
$$ ------------
$$ | O . O O O |
$$ | . O O O O |
$$ | O O O O O |
$$ | O O O O 2 |
$$ | O O O O X |
$$ -------------[/go]

= pass
= pass
= pass
= pass
= pass

In the encore White gets 1 net point for the extra Black pass plus 1 point for the captured stone plus 1 point for the point of territory on the 1-1 point.

Bill, let me try to understand your proposal with an encore phase, by using the following example:

$$W White to play
$$ ------------
$$ | X X . O X O . |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X . X O O |
$$ | . O X . X X X |
$$ -------------

Click Here To Show Diagram Code

[go]$$W White to play
$$ ------------
$$ | X X . O X O . |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X . X O O |
$$ | . O X . X X X |
$$ -------------[/go]

With japonese rule it follows:

$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O 4 |
$$ | X O O O X O O |
$$ | . O X X X O 6 |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------

Click Here To Show Diagram Code

[go]$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O 4 |
$$ | X O O O X O O |
$$ | . O X X X O 6 |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------[/go]

pass
pass
with a jigo result

Can you explain what happens when the encore is used (maybe after pass but I don't know) ?

Where is the encore?

[Bill Spight]

I know several people that tried to play go with friends, but gave up after their first game because they were unable to know who was the winner...

It is often said that go is a game with very simple rules. I nearly have a heart attack every time I read this. Go is probably the game with the most complicated rules in the world except role-playing games.

And baseball, golf, and contract bridge.

[Pio2001]

But by requiring allowing not just stupid, unbelievably foolish moves but also ANY LEGAL MOVE even when immediately suicidal then there is no such thing as a live group.

Except if a player does it on purpose. That may be a strategic option : to build a stupidly living group. The rule allows it.

[Gérard TAILLE]

Where is the encore?

$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------

Click Here To Show Diagram Code

[go]$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------[/go]

pass
pass

Bill I think I have resolved the two questions I had?
After the two passes above white may request an encore phase? Right?

Now, firsty it is white to play and not black as in the case of a resumption
and secondly black can retake the ko because though "passes before the encore do not count for stopping play in the encore" they count to lift the ko ban.
Is it right Bill?

BTW I have another question but let me first wait if the points above are correct.

[Bill Spight]

Where is the encore?

$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------

Click Here To Show Diagram Code

[go]$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------[/go]

pass
pass

Bill I think I have resolved the two questions I had?
After the two passes above white may request an encore phase? Right?

Now, firsty it is white to play and not black as in the case of a resumption
and secondly black can retake the ko because though "passes before the encore do not count for stopping play in the encore" they count to lift the ko ban.
Is it right Bill?

BTW I have another question but let me first wait if the points above are correct.

If passes and takes the ko back, how does Black retake the ko?

[Gérard TAILLE]

Where is the encore?

$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------

Click Here To Show Diagram Code

[go]$$W White to play
$$ ------------
$$ | X X . O X O 2 |
$$ | X X . O X X O |
$$ | X X . O X O . |
$$ | X O O O X O O |
$$ | . O X X X O . |
$$ | O O X 1 X O O |
$$ | . O X . X X X |
$$ -------------[/go]

pass
pass

Bill I think I have resolved the two questions I had?
After the two passes above white may request an encore phase? Right?

Now, firsty it is white to play and not black as in the case of a resumption
and secondly black can retake the ko because though "passes before the encore do not count for stopping play in the encore" they count to lift the ko ban.
Is it right Bill?

BTW I have another question but let me first wait if the points above are correct.

If passes and takes the ko back, how does Black retake the ko?

OK Bill I believe I begin to understand.
Here is another question:

White proposes to play a game with territory scoring, a komi = 0.5 and the "encore" procedure to resolve dispute. Black accepts and the game reaches the following position:

$$B Black to play
$$ ------------
$$ | . O O X O O . |
$$ | X . O X O O . |
$$ | X . O X O O . |
$$ | . . O X O O O |
$$ | O O O X O O O |
$$ | X X X X X O O |
$$ | . . . . X O . |
$$ -------------

Click Here To Show Diagram Code

[go]$$B Black to play
$$ ------------
$$ | . O O X O O . |
$$ | X . O X O O . |
$$ | X . O X O O . |
$$ | . . O X O O O |
$$ | O O O X O O O |
$$ | X X X X X O O |
$$ | . . . . X O . |
$$ -------------[/go]

Black, seeing 4 points for white against 4 points for her is ready to resign but suddenly black remembers white proposal made before the beginning of the game and decide to continue the game:

$$B Black to play
$$ ------------
$$ | . O O X O O . |
$$ | X . O X O O 3 |
$$ | X 1 O X O O . |
$$ | . . O X O O O |
$$ | O O O X O O O |
$$ | X X X X X O O |
$$ | . . . . X O . |
$$ -------------

Click Here To Show Diagram Code

[go]$$B Black to play
$$ ------------
$$ | . O O X O O . |
$$ | X . O X O O 3 |
$$ | X 1 O X O O . |
$$ | . . O X O O O |
$$ | O O O X O O O |
$$ | X X X X X O O |
$$ | . . . . X O . |
$$ -------------[/go]

pass
pass
pass

Now white designs stone as being dead but black disagrees, starts a "strategic" dispute and requests an "encore" procedure. Now white realizes the meaning of black and recognizes that after the "encore" black wins the game!

I hope I am wrong Bill!

[Bill Spight]

Here is another question:

White proposes to play a game with territory scoring, a komi = 0.5 and the "encore" procedure to resolve dispute. Black accepts and the game reaches the following position:

$$B Black to play
$$ ------------
$$ | . O O X O O . |
$$ | X . O X O O . |
$$ | X . O X O O . |
$$ | . . O X O O O |
$$ | O O O X O O O |
$$ | X X X X X O O |
$$ | . . . . X O . |
$$ -------------

Click Here To Show Diagram Code

[go]$$B Black to play
$$ ------------
$$ | . O O X O O . |
$$ | X . O X O O . |
$$ | X . O X O O . |
$$ | . . O X O O O |
$$ | O O O X O O O |
$$ | X X X X X O O |
$$ | . . . . X O . |
$$ -------------[/go]

Black, seeing 4 points for white against 4 points for her is ready to resign but suddenly black remembers white proposal made before the beginning of the game and decide to continue the game:

$$B Black to play
$$ ------------
$$ | . O O X O O . |
$$ | X . O X O O 3 |
$$ | X 1 O X O O . |
$$ | . . O X O O O |
$$ | O O O X O O O |
$$ | X X X X X O O |
$$ | . . . . X O . |
$$ -------------

Click Here To Show Diagram Code

[go]$$B Black to play
$$ ------------
$$ | . O O X O O . |
$$ | X . O X O O 3 |
$$ | X 1 O X O O . |
$$ | . . O X O O O |
$$ | O O O X O O O |
$$ | X X X X X O O |
$$ | . . . . X O . |
$$ -------------[/go]

pass
pass
pass

Now white designs stone as being dead but black disagrees, starts a "strategic" dispute and requests an "encore" procedure. Now white realizes the meaning of black and recognizes that after the "encore" black wins the game!

I hope I am wrong Bill!

The Spight rules are not Japanese rules. An encore is not necessary to resolve any dispute about life and death. can pass.