Life In 19x19

If you let things like ko on other parts of the board impact terminology, it's lame in other regards, too. Take this for example:

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[go]$$Bcm1
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

Has black enclosed the corner? If so, you might call this a corner enclosure. But that's not precise, is it? It's actually a *conditionally* enclosed corner. Because, what if white has a lot of ko threats, and captures these two stones??

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[go]$$Wcm1
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . 7 . . |
$$ | . . . , . . . . . , . . . . 9 1 C 5 . |
$$ | . . . . . . . . . . . . . . . . 3 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

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[go]$$Wcm11
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . 3 . . . . |
$$ | . . . . . . . . . . . . . 1 C 5 O . . |
$$ | . . . , . . . . . , . . . . O O C O . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

So it's not a corner enclosure after all! Only a *conditional* corner enclosure. Haha!

Ok, yeah. It's a *conditional* corner enclosure. But how practical are we being here, now? Let's just keep a sensible terminology, and read the kos separately.

There are many things in go that are "conditional" in a strict sense. But it's widely used terminology to mean "conditionally alive" to be "alive if you win the local ko". Indeed, the 無条件 that Bill referred to earlier is literally, unconditional.

Kirby wrote:There are many things in go that are "conditional" in a strict sense. But it's widely used terminology to mean "conditionally alive" to be "alive if you win the local ko".

You mean "alive if you win the ko" ? Isn't it the same thing as "dead if you loose the ko" ?

I prefer saying "dead / alive / ko / depends on who's turn it is".

Pio2001 wrote:

Kirby wrote:There are many things in go that are "conditional" in a strict sense. But it's widely used terminology to mean "conditionally alive" to be "alive if you win the local ko".

You mean "alive if you win the ko" ? Isn't it the same thing as "dead if you loose the ko" ?

It is the same, yes. But in problem books, it's standard terminology to say "conditionally alive". I've also seen problems where you're supposed to kill, and in that case, I've seen terminology that might be translated as, "conditionally capture the stones".

..."alive if you win the ko" ? ...same... as "dead if you loose lose the ko" ?

Other wordings include "It's ko for life/seki", "It's a (t-step) ko", etc.

I prefer saying "dead / alive / ko / depends on who's whose turn it is".

Not my impression: usually Go problems specify the turn ( normally if the opposite color goes first, the advantage becomes overwhelming and the problem thus trivial ).

Examples:

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[go]$$c Another one
$$ ----------------------
$$ | . . . . . X . . . |
$$ | . O O O . O X . . |
$$ | . . . X O . . X . |
$$ | . O . X . O O X . |
$$ | . . O . X X X . . |[/go]

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[go]$$c whats wrong with this as white?
$$ ----------------------
$$ | . . . . . X . . . |
$$ | . O O O 4 O X . . |
$$ | . . . X O 1 3 X . |
$$ | . O . X 2 O O X . |
$$ | . . O . X X X . . |[/go]

Instead of there's a much better move.

hyperpape wrote:

Bill Spight wrote:(Note: That is the traditional way of using the term unconditionally alive. In some contexts people use the term to mean that a group is alive even if its owner always passes. But in problems it means that a group is alive with correct play against any attack, except possibly in a ko fight.)

Bill, I would have thought the lower left counts as unconditionally alive by that definition? Against any attack, black can live.

Sorry for the late reply, I did not see this before.

You are correct. But the diagram is not a problem.