J2003 problem

[Gérard TAILLE]

$$B
$$ +---------------------------+
$$ | . X X O . O X O . O X X . |
$$ | O O X O O O X O O O X O O |
$$ | O X X X O O X O O X X X O |
$$ | . . X X O . X . O X X . . |
$$ -----------------------------
$$

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------+
$$ | . X X O . O X O . O X X . |
$$ | O O X O O O X O O O X O O |
$$ | O X X X O O X O O X X X O |
$$ | . . X X O . X . O X X . . |
$$ -----------------------------
$$[/go]

What is the result of this game in J2003? It is not quite clear for me if it is a complete seki or if the four black stones in the middle are dead (it seems it is the only group of stones capturable).

[jann]

this right side ko shape was already presented by le_4TC

The shape itself is well known (the original/complex one even has a name), but the inverse-bent4 seems unnamed so far.

[jann]

$$B
$$ +---------------------------+
$$ | . X X O . O X O . O X X . |
$$ | O O X O O O X O O O X O O |
$$ | O X X X O O X O O X X X O |
$$ | . . X X O . X . O X X . . |
$$ -----------------------------
$$

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------+
$$ | . X X O . O X O . O X X . |
$$ | O O X O O O X O O O X O O |
$$ | O X X X O O X O O X X X O |
$$ | . . X X O . X . O X X . . |
$$ -----------------------------
$$[/go]

What is the result of this game in J2003? It is not quite clear for me if it is a complete seki or if the four black stones in the middle are dead (it seems it is the only group of stones capturable).

This doesn't seem a finished position, with two indirect kos W should probably play on in normal game.

[Gérard TAILLE]

$$B
$$ +---------------------------+
$$ | . X X O . O X O . O X X . |
$$ | O O X O O O X O O O X O O |
$$ | O X X X O O X O O X X X O |
$$ | . . X X O . X . O X X . . |
$$ -----------------------------
$$

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------+
$$ | . X X O . O X O . O X X . |
$$ | O O X O O O X O O O X O O |
$$ | O X X X O O X O O X X X O |
$$ | . . X X O . X . O X X . . |
$$ -----------------------------
$$[/go]

What is the result of this game in J2003? It is not quite clear for me if it is a complete seki or if the four black stones in the middle are dead (it seems it is the only group of stones capturable).

This doesn't seem a finished position, with two indirect kos W should probably play on in normal game.

Yes Jann I know. But my question is here only to understand how is determined territories according to the rule. Here it is not quite clear for me.

[jann]

$$B
$$ +---------------------------+
$$ | . X X O . O X O . O X X . |
$$ | O O X O O O X O O O X O O |
$$ | O X X X O O X O O X X X O |
$$ | . . X X O . X . O X X . . |
$$ -----------------------------
$$

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------+
$$ | . X X O . O X O . O X X . |
$$ | O O X O O O X O O O X O O |
$$ | O X X X O O X O O X X X O |
$$ | . . X X O . X . O X X . . |
$$ -----------------------------
$$[/go]

These rules seem to bound local enable by the same player's uncapturable or reestablishable strings. So in your example W can freely throw away the edges, thus middle B string looks capturable without enabling.

I think a local enable rule is almost as big a theoretical flaw as a global ko pass. You definitely want to detect ANY kind of problem with a capture, never allow throwing away large parts without consequence (remember your early rules: global play without global enable).

[RobertJasiek]

a local enable rule is almost as big a theoretical flaw as a global ko pass.

In which sense do you speak of a "theoretical flaw"? What, IYO, is the theoretical flaw of a local enable rule? What, IYO, is the theoretical flaw of a global ko pass?

[Cassandra]

"Local enable" is just as little a theoretical flaw as "global enable" or "rebirth enable" is.
"Global ko-pass" is just as little a theoretical flaw as "ko-pass for every single ko" or "no ko-pass" is.

In each case (and also each combination of these) a consistent, error-prone ruleset can be built around.

You may not like the game that comes out of it.
However, this is SOLELY a result of your unfulfilled expectiations.
If you can't live with that, just play another game. There is more than enough choice.

[jann]

What, IYO, is the theoretical flaw of a global ko pass?

The theoretical defect of such rule is it may allow passing for two remote ko fights in one move, for non-Japanese results

What, IYO, is the theoretical flaw of a local enable rule?

You definitely want to detect ANY kind of problem with a capture, never allow throwing away large parts without consequence

In which sense do you speak of a "theoretical flaw"?

In both of the above cases the problem is the same: the rule invention does not correspond to a meaningful go concept.

• A local ko pass rule (as used in Japanese rules) has a theoretical meaning of complete ko isolation.
• A global enable rule (again as used in J89) has a theoretical meaning of detecting any kind of negative consequence/compensation anywhere that may be attached to the capture, which could mean it is not really a simple dead stone capture from sure territory.

A global ko pass rule and a local enable rule can easily lead to incorrect results (see the examples in this thread for both) because they are random inventions without such theoretical ground.

[Cassandra]

A global ko pass rule and a local enable rule can easily lead to incorrect results (see the examples in this thread for both) because they are random inventions without such theoretical ground.

What is YOUR "incorrect" based on IN the respective rule set(s)?

Are YOU sure YOU are IN the right game?
Why don't YOU play a game that follows YOUR interpretation of "meaningful"?

[Cassandra]

A global ko pass rule and a local enable rule can easily lead to incorrect results (see the examples in this thread for both) because they are random inventions without such theoretical ground.

Same task as for Gérard in another thread:

$$B
$$ +---------------------+
$$ | X X . O X X O X X . |
$$ | X O O O X . O X O O |
$$ | . O X X X X O X X O |
$$ | O O X . O O O X . . |
$$ -----------------------
$$

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------+
$$ | X X . O X X O X X . |
$$ | X O O O X . O X O O |
$$ | . O X X X X O X X O |
$$ | O O X . O O O X . . |
$$ -----------------------
$$[/go]

Reverse tsume-go.
Please be so kind to show us the last seven moves before this position was reached.

[RobertJasiek]

First are the rules, then come the strategic concepts.

Do you want to make that

First are the strategic concepts, then come the rules?

If one invents a new game, rules design can fit to produce some desired strategic concepts. Go is an exception to game design because rules and strategic concepts were developed in parallel. Even worse, Japanese professional players developed their particular understanding of some desired dependency between rules and strategic concepts but furthermore changed it over time.

Life was perceived as a local concept unless covering the whole board but play for clarifying local life is global. Ko is both local as to currently prohibited intersections and global as to availability of plays.

Hence, it is difficult to identify a rules concept as a flaw on the grounds of general concepts.

[jann]

First are the rules, then come the strategic concepts.
Do you want to make that
First are the strategic concepts, then come the rules?

Even when creating a new game from scratch you need rules that are not too arbitrary and carry some concept, to get people interested and convince them there is intellectual value in your game. With Go, the game and its rules already exist for a long time. So not only your newly written rules need to be convincing and consistent, they need to match the real game as well.

$$B
$$ +--------------------
$$ | X X . O X O X O O O X X X |
$$ | X O O O X O X O . O X . O |
$$ | . O X X X O X . O O X O O |
$$ | O O X . X O X X X O X X O |
$$ | O X X X . O . X O O X . . |
$$ ----------------------
$$

Click Here To Show Diagram Code

[go]$$B
$$ +--------------------
$$ | X X . O X O X O O O X X X |
$$ | X O O O X O X O . O X . O |
$$ | . O X X X O X . O O X O O |
$$ | O O X . X O X X X O X X O |
$$ | O X X X . O . X O O X . . |
$$ ----------------------
$$[/go]

In the wider version of this example, the bent4 corner itself seem to be alive in your rules. Capturing enables a new permanent W stone on dame next to his 10 stones, barely within your enable region. But your rules are not consistent. It matters if the right side is single ko or double ko (since your ko pass works vs double kos and vs non-ko-based threats, only not vs single kos), and it also depends on the middle (since your enable rule doesn't see the right edge, it matters if B or W gets the last play on dame after the seki collapses).

In comparison, Japanese rules say something like "bent4 is dead since ko fight is not allowed in confirmation, it doesn't matter if the unremovable threat is near or far, neither if it is single ko, double ko or something else". Which can be questioned of course (Japanese isn't my rules preference), but at least it's logical and consistent.

[Gérard TAILLE]

First are the rules, then come the strategic concepts.
Do you want to make that
First are the strategic concepts, then come the rules?

Even when creating a new game from scratch you need rules that are not too arbitrary and carry some concept, to get people interested and convince them there is intellectual value in your game. With Go, the game and its rules already exist for a long time. So not only your newly written rules need to be convincing and consistent, they need to match the real game as well.

$$B
$$ +--------------------
$$ | X X . O X O X O O O X X X |
$$ | X O O O X O X O . O X . O |
$$ | . O X X X O X . O O X O O |
$$ | O O X . X O X X X O X X O |
$$ | O X X X . O . X O O X . . |
$$ ----------------------
$$

Click Here To Show Diagram Code

[go]$$B
$$ +--------------------
$$ | X X . O X O X O O O X X X |
$$ | X O O O X O X O . O X . O |
$$ | . O X X X O X . O O X O O |
$$ | O O X . X O X X X O X X O |
$$ | O X X X . O . X O O X . . |
$$ ----------------------
$$[/go]

In the wider version of this example, the bent4 corner itself seem to be alive in your rules. Capturing enables a new permanent W stone on dame next to his 10 stones, barely within your enable region. But your rules are not consistent. It matters if the right side is single ko or double ko (since your ko pass works vs double kos and vs non-ko-based threats, only not vs single kos), and it also depends on the middle (since your enable rule doesn't see the right edge, it matters if B or W gets the last play on dame after the seki collapses).

In comparison, Japanese rules say something like "bent4 is dead since ko fight is not allowed in confirmation, it doesn't matter if the unremovable threat is near or far, neither if it is single ko, double ko or something else". Which can be questioned of course (Japanese isn't my rules preference), but at least it's logical and consistent.

BTW what is the result in J2003 for the above position. It seems all groups are alive except the four white stones at the right => black wins by 11 points. Is it true?

[jann]

You got me thinking for a moment - nice point on the 4 stones!

[Cassandra]

Simply allow hypothetical play inside local-2 only, and everything will be fine.