Robert Pauli: Dear Wilton, some humble suggestions and stupid questions :--)
So far - still puzzled by the rest . . .
Robert Pauli: Kee, call'em fluid rules - they change at least once a week ;-)
Wilton Kee: Sorry about that. Hopefully it seems converging to a concrete one.
Ban deletion, despite being played on one position, has its effect of removing bans on every previous position.
Similarly, ban recovery, despite occurring on one position when such position is repeated, has its effect of recovering bans on every previous position.
Ban deletion may not be played on the same position twice. However, it does not mean that the ban effect to a position may not be activated / deactivated twice. This can happen when ban deletion is played on two different later positions.
Robert Pauli: Wilton, is the life cycle of a position with regard to B
1 -> 2 -> 3 -> 4
with
and
?
Recovered does not imply undeletable. Therefore, 3 may go to 2. Actually we may never know if a ban on a position is 2 or 4.
Robert Pauli:
Think my problem was confusing direct with indirect ban deletions, Wilton.
A direct ban deletion on one position indirectly deletes bans from all former positions. Any position may be subject to a direct ban deletion once only, but there is no limit on the number of indirect ban deletions it may take. As I get it now, B5 is only referring to direct ban deletions, whereas B3 refers to direct as well as indirect ones.
Let me try to put it in other words:
After cutting apart the sequence of positions at each point a ban deleting pass occurred,
Now right?
You are right. However, I do not quite follow your third statement:
Could you please explain a little bit more?
Sorry for being cryptic, Wilton. It's: position, move, position, move, etc. - any action being a "move", even a pass. Now, since the position right before a (ban-deleting) pass is the same as the one after it, but this isn't the intentional repetition we want to enable, we have to allow a second.
You sidestep this by only banning repetitions made via stones, which is fine, but please remove the confusion between direct and indirect ban deletion, it's cruical.
I choose not to use terms like "direct" or "indirect" ban deletion just because I believe things get even more complicated when more terms are defined.
This is not an easy sentence to digest at a first glance, I admit. But as long as it does not produce confusion, I think it is fine to keep it. Do you agree?
No, sorry. Keep it as simple as possible, but not simpler - as Albert would put it.
Reading
A player may not delete ban on a position on which ban has ever been deleted.
strictly - and how else should one read rules? - prevents ban deletion in all positions that occurred prior to any ban deletion since the ban was removed from them as well.
If we have P1 m1 P2 m2 P3 and neither m1 nor m2 was a ban deletion, then P3 neither may repeat P1 nor P2 - each banned. If it continues with m3 P4 m4 P5 m5 and m3 is a ban deletion, implying P3 = P4, then P5 may repeat P1 - P4. If P5 = P3, the rule above prevents m5 to be a ban deletion, as intended. However, if P5 = P2 you want to allow ban deletion, but your rule does not: m3 deleted a ban from P2, not?
For other readers' information, "P" stands for position and "m" stands for move in what written above.
First of all, if m3 is a ban deleting move (pass), it is correct that P3 = P4. However, P5 may not repeat P4 (= P3) because m3 only deletes P1 - P3.
If P5 = P3, then m5 must be a pass (as this implies P5 = P4). However, you are right that m5 cannot be a ban deleting pass because P3 (= P5) has been ban-deleted by m3.
If P5 = P2 and P2 <> P3, then m5 can be a ban deleting pass if there has been no ban deleting pass made on P2. m3 deleted a ban from P2 but not a chance to make a ban deleting pass on P2.
You're right, P5 may only repeat P1 - P2. I slipped (ignoring my own "none of the subsequences may contain any of its positions more than once").
You're also right in that m5 necessarily has to be a pass - but that wasn't my intention, sorry. To be more general I should have added, say, P6 m6 P7 m7 P8 m8, with P5 - P7 being fresh positions, and asked about P8 and m8 instead, but since it doesn't matter, let's leave it as is.
With what I still can't agree, however, is that
m3 deleted a ban from P2 but not a chance to make a ban deleting pass on P2.
If "m3 deleted a ban from P2" and the rule is
A player may not delete ban on a position on which ban has ever been deleted.
anybody will conclude that no more ban deletion is possible on P2 - no matter what the rule designer's intention actually was.
Wilton, by no means do I want to push you to use "direct/indirect". This just was my quick and dirty way to make things clear.
The problem seems to come from being able to read "ban deletion" in two ways. First, as technical term, a special kind of pass, and, second, as a description of an effect on a position, no longer being banned. How about "ban-deleting pass" versus "ban deletion"? For instance:
A 5. A play can either be a stone placement, a ban-deleting pass, or a position-affirming pass.
B 4. A player may not place a stone to produce a position which has ever occurred unless its last occurrence was followed by a ban-deleting pass and such pass was not followed by a recovery.
B 5. A player may not pass ban-deleting in a position in which this ever happened.
So far the first usage. The second usage only appears in B3, as far I see. However, why isn't
B 3. A stone placement recovers ban when it produces a position on which ban has ever been deleted.
simply
B 3. A stone placement recovers ban when it produces a position which already occurred.
?
The reason is simple - because it is just not the case.
Rule B 3 says ban recovered when a stone placement produces a position on which a ban-deleting pass has been made before. Therefore, this "ban-deletion" is still on its first usage.
To summarize:
1. Ban-deleting pass:
- always refers to a specific pass
- actively chosen by a player
2. Ban-recovering stone placement:
- always refers to a specific stone placement
- not actively chosen by a player
- a stone placement is ban-recovering when a ban-deleting pass has been made on the resulting position
3. To test whether a stone placement is valid:
- first check if the resulting position has occurred before.
- If no, valid. If yes, check if a ban-deleting pass has been made after its last occurrence.
- If no, invalid. If yes, check if it is followed by a ban-recovering stone placement.
- If yes, invalid. If no, valid.
4. To test whether a ban-deleting pass is valid:
- check if a ban-deleting pass has been made on the same position.
- If yes, invalid. If no, valid.
So the usage in B3 also is in the first sense (ban-deleting pass) - I see:
B 3. A stone placement recovers ban(s) when it produces a position ever produced by a ban-deleting pass.
Let me still recommend my distinction to enable (meta-)talk of one ban-deleting pass deleting ban from several positions.
Thank you for the step-by-step summary. Very good! However, shouldn't point 3 strictly be
3. To test whether a stone placement is valid:
- first check if the resulting position has occurred before.
- If no, valid. If yes, check if a ban-deleting pass has been made after its last occurrence without being followed by a ban-recovering stone placement.
- If no, invalid. If yes, valid.
?
Wilton Kee: What is the difference?
Another question: If only one ban-deleting pass ever has occurred and nobody performs a second one, no ban-recovering stone placement actually can happen. Right?
Wilton Kee: Right.
Guess I got part B now (:-). Let's move on.
I'd prefer
G2. The area of a player consists of all her stones and territories in the final position.
since anything of herself without two eyes was kicked off during testifying and we want to refer to her complete area, no matter if it comes in one part or not.
Wilton Kee: It is a good suggestion.
Let me also (humbly) correct some English:
Wilton Kee: Thank you for your valuable check.
Regarding the last point and "consolidating phase" / "consoldated position", you might consider to use
Wilton Kee: I understand "chilled position" may not be a good term and "final position" does cause some confusion. I just think of using "scoring position" to refer to the final position in normal phase and "testified position" to refer to the position after testifying phase. What do you think?
It's not quite clear how the extra phases are restricted by positions that occurred outside of them. Guess they don't matter. Right?
Oh! it seems there's a bug in G4a. Shouldn't it be
A player gets one point from every not by herself occupied intersection in the chilled position if it belongs to her area in all final positions.
Otherwise you're ignoring territory beneath dead stones, which still are around in the chilled position.
Wilton Kee: It is not a bug. Actually instead of the player getting one point, it's the one who owns the dead stone loses one point.
It seems that your "Japanese" territory scoring doesn't treat bent four correctly. Example:
Ignoring when exactly White has to capture in the seki to earn points, in Japan this will end as B+9
(= 12-3 = White takes two, Black throws in one, and White takes it - finished, with four white stones dead in bent four.)
Under your rules, however, White will hold back the capture to keep a ko threat. This will prevent Black from starting the ko in any consolidating phase: only B+2. Right?
Wilton Kee: I admit. We actually cannot use positional superko in testifying phase if we are going to strictly follow Japanese Rule. I will work on it. Any suggestion?
Position affirmed by all, but no agreement on declaration: chilled, nothing removed.
No matter if Black is tested or White, Black "seals off" a 3x3 area in either case.
According to G4a, Black receives 3 points; according to G4b, White receives -3 points: B+6.
But, of course, this is B+9. G4a missed to count the intersections covered by the dead white stones.
If the left end is seki, as usual, this is W+12. Under your rules, however, we have to check two lines:
So, left end and white center belong to nobody due to changing ownership. The rest is W+8. Right?
Wilton Kee: Robert, I have amended quite a lot in this version. I am sure the amended version does answer all your questions above, despite the fact that new questions may arise. :)
The left side of the above diagram would always be a seki under the amended rule because of the created-group superko rule (stronger than situational superko rule). For normal ko, it is equivalent to the philosophy in Japanese Rule that only passes can lift the ko ban. Therefore, the amended version also gives W+12 in this case.