Author: Andreas Herrmann
Date: 09:58:42 11/22/02
Go up one level in this thread
On November 22, 2002 at 11:35:38, Tony Werten wrote: >On November 22, 2002 at 10:39:16, Uri Blass wrote: > >>On November 22, 2002 at 10:30:34, Robert Hyatt wrote: >> >>>On November 22, 2002 at 07:21:13, Uri Blass wrote: >>> >>>>On November 22, 2002 at 05:50:09, Omid David Tabibi wrote: >>>> >>>>>Vincent, >>>>> >>>>>You haven't read the article yet. READ IT. I have described everything I have >>>>>done quite clearly, and have presented the results. All the node counts are also >>>>>available at my website. >>>>> >>>>>Regarding your checkmate question: except for the "Mate in 4" and "Mate in 5" >>>>>positions which I was interested to know only if the checkmating was found or >>>>>not, in all other test positions (ECM, WCS, Neishtadt) the search was conducted >>>>>to the mentioned depth even if a checkmate is found at eariler plies. This was >>>>>done in order to ensure that the fixed depth results are comparable in terms of >>>>>tree size. >>>>> >>>>>Omid. >>>> >>>>What do you search after finding a mate? >>>>Does genesis search for a shorter mate and in this case does it knows not to >>>>search when it get ply that means that no shorter mate can be found? >>>> >>>>Movei simply stop searching after finishing an iteration with mate score. >>>> >>>>Uri >>> >>> >>>I would suspect he does like most everyone else. Search until you reach depth >>>2*N-1 where N is the mate depth as in mate in 9. I need to search 17 plies to >>>verify that no shorter mate than mate in 9 exists... >> >>I do not know what most do but I do not care after finding a mate to find the >>shorter mate. >> >>The result is the same even if I do not find the shortest mate. >>I care only to finish the iteration. > >You'll care when you add tablebase support. > >When there are 6 pieces on the board and your program sacrifies his queen to >find a checkmate in 123, you'd wish it had searched a bit longer to find the >mate in 4. Hi Tony, but then you must be in depth 245 to cut the search by checkmate in 123 and search abort after 2*N-1. In previous versions i have also finished the search after 2*N-1. In my current version i finish my search after 2*N+2, because of Nullmove and other pruning algos. But it's mainly interresting to search a little bit deeper if there was found a mate for the opponent, perhaps in some rare cases a draw will be find 2 or 3 plys deeper. Andreas PS: Thanks again for your DLL. Works fine :)
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