luigi wrote:
Could you please provide a clear answer as to whether the following rulesets are fully equivalent to each other, without exception?:
A: Area scoring. No suicide. Positional superko. Button not considered a pass, worth 0.5 points for whoever takes it. Komi 7.
B: Area scoring. No suicide. Positional superko. Button not considered a pass, worth 1 point for White and 0 points for Black. Komi 6.5.
First, the status of the button matters to positional superko. All board positions before the button is taken are different from all board positions after the button is taken. So when the button is taken we can forget all positions earlier than the current position. They cannot be replicated.
With a 7 point komi we have the following button, represented as a game.
Code:
B
/ \
½ -½
From the button, B, Black can move to a position worth ½ pt. or White can move to a position worth -½ pt., i.e., ½ pt. for White. Now let's add the komi to those results.
Code:
B
/ \
-6½ -7½
So the combination of button and komi means that Black can take the button for an effective komi of 6½, while White can take the button for an effective komi of 7½.
With a 6½ point komi we have the following button, represented as a game.
Code:
B
/ \
0 -1
From the button, B, Black can move to a position worth 0 or White can move to a position worth -1 pt., i.e., 1 pt. for White. Now let's add the komi to those results.
Code:
B
/ \
-6½ -7½
All same same.