Author: Ernst A. Heinz
Date: 08:58:10 08/25/00
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Hi Christophe, >On August 25, 2000 at 11:01:45, Ernst A. Heinz wrote: > >>Hi Christophe, >> >>>Yes, but have you seen my own reply to your answer? >>> >>>It's not to be picky actually. I think there is a serious problem with the trick >>>when you have a QSearch, and I wanted to have your opinion. >> >>Yes, still as I said before -- personally, I do not think that >>the quiescence search is the _real_ problem. A variable-depth >>capture-only quiescence without any kind of alpha-beta related >>stuff (e.g. futility pruning and lazy evaluation) would be a >>perfectly fine black-box routine for scoring horizon nodes that >>should work together with the negascout "trick" _without_ losing >>theoretical correctness. The "trick" only fails with variable >>depths in the _main_ search layer because that is where the >>true fixed-depth 2-ply research always yields the same result as >>the original zero-window search. >> >>Have you read Dave Gomboc's answer where he tells about Jonathan >>Schaeffer's experience with the negascout "trick". As soon as he >>added extensions in the _main_ search, he ran into problems. If, >>as I assume, he already had a quiescence search before, this >>would provide empirical evidence and support for my argument. > >I do not disagree with you about extensions, but I disagree about SQearch, even >it is very simple. Have you read my other post in which I explain what the >problem is, in my opinion? Yes, I have read it -- that is why I hypothetically assume a variable-depth quiescence search above which is _independent_ of alpha and beta. Thereby I meant to show that variable-depth search in the scoring of horizon nodes does not _necessarily_ kill the negascout "trick", i.e., it is not any variable-depth search below horizon nodes which kills the "trick" but variable depths in the main search. What else have I overlooked in your other post? Cheers, =Ernst=
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