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Sesqui-Eyed Go

Posted: Tue May 23, 2023 12:51 pm
by luigi
Consider a Go variant where Black cannot place a stone on a point where its group would have no liberties, not even to make a capture, while White can play as usual.

Two questions:
  • How many handicap stones should Black receive to make the game fair?
  • Otherwise, which reverse komi value would be needed to make the game fair?

Re: Sesqui-Eyed Go

Posted: Wed May 24, 2023 5:06 am
by ArsenLapin
You call this variant "sesqui-eyed go", which appears to suggest that an eye and a half is enough to live.

But actually, unless I misunderstand, even one false eye is enough for White to be definitively alive.

Any White group that manages to make one of these three shapes would be definitively alive:
Image

Thus I believe the name "quarter-of-an-eye go" would be more appropriate than "sesqui-eyed go".

This would make it so easy for White to make live groups, and so hard for Black to kill white stones, that I suspect White would be able to play super aggressively and kill all black stones on the board.

Re: Sesqui-Eyed Go

Posted: Wed May 24, 2023 5:09 am
by ArsenLapin
You call this variant "sesqui-eyed go", which appears to suggest that an eye and a half is enough to live.

But actually, unless I misunderstand, even one false eye is enough for White to be definitively alive.

Any White group that manages to make one of these three shapes would be definitively alive:
Click Here To Show Diagram Code
[go]$$Wcm8
$$ -------------------
$$ | . O . . O . O . . |
$$ | O . . . . O . . . |
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . . O . . . . . |
$$ | . . O . O . . . . |
$$ | . . . O . . . . . |
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ -------------------[/go]
Thus I believe the name "quarter-of-an-eye go" would be more appropriate than "sesqui-eyed go".

This would make it so easy for White to make live groups, and so hard for Black to kill white stones, that I suspect White would be able to play super aggressively and kill all black stones on the board.

Re: Sesqui-Eyed Go

Posted: Wed May 24, 2023 10:45 am
by Schachus
I assume this means for example black cannot capture any Kos etc.

Really a lot of handicaps. I cannot prove it, but I would definitely fancy my chances as white on 9 stones against an equally strong opponent using those rules

Just as an example: it is very hard to kill a white 2-2 stone, even with lots of black stones around. That just means its so tough for black to make a usual base in the corner, cause white can just 2-2 invade, live and take blacks eyes in the corner away.

Re: Sesqui-Eyed Go

Posted: Fri Jun 16, 2023 1:54 pm
by luigi
ArsenLapin wrote:You call this variant "sesqui-eyed go", which appears to suggest that an eye and a half is enough to live.
I called it "sesqui-eyed Go" because one player lives with one eye and the other needs two.