Ko monster

Path: <= CGT path =>
  Difficulty: Expert   Keywords: Ko, Theory

The komaster of a ko is the person who can win it without having to ignore a ko threat. The koloser has to make at least one play elsewhere in exchange for the ko.[11]

I coined the term, komonster for a komaster who can use extra ko threats to make an additional gain. This gain comes from a reduction in the size of the play or plays made in exchange for the ko. (Sometimes it may come from a smaller alternative local to the ko, such as filling one leg of a multi-step ko.) [10] If the koloser can make a 2 point play (miai counting) in exchange for the ko, the komonster may delay winning the ko to exchange it for a 1 1/2 point play. The average gain from the delay is the difference, or 1/2 point. We call this difference the drop in temperature.

A pair of plays of the same size (a miai pair) may effectively take away one ko threat from a potential komonster, because the temperature stays the same between them instead of dropping. In that regard we may consider them as a kind of defensive ko threat. They do not help win the ko, but they may limit the damage. I call such a miai pair a virtual, or tertiary ko threat.


[10] tderz: Bill, how about an example? (with diagrams)
[11] tderz: " ... has to make at least one play elsewhere ... " Isn't this always the case? RJ would include PASSes in examples for plays.

We could only imagine one very academic example where filling/winning the ko is the last move and the loser of the ko has no valid/legal play to make (except PASSing).

Hence even then the information given in the quote seems trivial and cannot serve as definition for koloser (imagine that PASS is excluded and winning the ko was the last move.

If the quote should be a definition, then losing the ko and not being able to play elsewhere would make the koloser not a koloser? -> ad absurdum !

Bill: I guess I was not clear. I was not defining koloser, I just meant to say that the koloser could not complete a ko threat in exchange for the ko, but could only make a play elsewhere. If the koloser has to pass, then the komaster does not need an extra ko threat.

Anon The definition suggests that the komonster is a type of komaster, who can use extra ko threats to gain more from the ko exchange, but how can a komaster lose anything from a ko exchange? After all, a komaster is defined as a player who can win a ko without ignoring a ko threat.

Path: <= CGT path =>
Ko monster last edited by on January 29, 2013 - 14:27
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