115WS Notcher

    Keywords: Life & Death

See table of notchers. Alive, unsettled (with or without ko) or dead?


Black plays and lives.


White makes ko.

emeraldemon: It seems to me that this is a 2 step ko for black:

symplicity: Actually, this is just an ordinary ko where white has a local ko threat. Whoever wins the ko only has to ignore one move by the opponent elsewhere, just as in a regular ko. In a two-step ko, for player for which the ko is two-step would have to ignore *two* moves elsewhere in order to win the ko.

emeraldemon: Thanks, I had my terms confused. Actually, it looks like white has two local threats.

The term, two step ko, is ambiguous. Best to avoid it.

white takes ko  
black finds threat, white defends  
black has to descend  
black finds another threat  

Of course, depending on the situation, black 8 may be a threat, or generate threats around a.

115WS Notcher last edited by on July 9, 2020 - 11:15
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