Author: Uri Blass
Date: 13:44:32 09/05/04
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On September 05, 2004 at 15:58:39, Bas Hamstra wrote: >On September 05, 2004 at 14:56:14, Uri Blass wrote: > >>On September 05, 2004 at 14:30:01, Bas Hamstra wrote: >> >>>>My program has this in relation to checks, all conditionally compilable: >>>> >>>> 1) all checks-evasions in quiescence, unlimited occurrences >>>> 2) all checks-evasions in main search, unlimited occurrences >>>> 3) all checking-moves in quiescence, at the first ply of quiescence >>>> >>>>These are the three extensions. Only #1 and #2 have proved useful. >>> >>>Impossible. When I did 3) it solved wac141 within one second, using a mate >>>extension of a full ply. It takes 30.000 nodes and 6 plies to anounce M6. >> >>With mate extension of a full ply your search will explode because >>there are positions when there are a lot of checks and every reply to check is >>a mate threat. > >Not in my search. But I have taken actions to prevent "stapling" of useless >matethreats. I have done a full ply mate-extend in Tao 5.4 without problems. > >>6 plies to see the mate and only 30000 nodes. >>It seems to me hard to believe it espacially when I expect your search with >>full ply extension for mate to explode. > >See above for the explosion. I am not saying a full ply mate-ext is best, but I >have used it for years and it worked fine. This is probably also a matter of >what your qsearch can do. Mine can solve simple multi-move mates. Mine can also see some mates in 2 but the problem is that it seems that finding mate threat is not enough and you need also to store the result in the hash tables and use the hash tables to detect mate threat and extend them in order to find mate scores. I did not do and the implementation that helped me to find Qxf4 at depth 6 was simply to increase depth after undoing null move that returned a score of threat mate. Uri
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