Author: Renze Steenhuisen
Date: 08:45:33 04/07/04
Go up one level in this thread
>>>>>>>How important is it to hash in the castling rights and en-passant fields? >>>>>> >>>>>>Very important; it will go wrong at a tournament otherwise. >>>>> >>>>>Yes, I read of some (your?) tournament issue? >>>>> >>>>>But is it important for my results, now? Because I am using the starting >>>>>position as test position... >>>> >>>>If you search above a ply or 4 sure, as then you can already start capturing en >>>>passant. >>> >>>Should I put it in first, could that really be the problem? >> >>Depends upon how you measures errors/collissions. > >>Define collision first. >> >>(1) two different positions produce the same hash signature... >> >>(2) two different hash signatures address the same table entry... >> >>(1) should not happen with 64 bit signatures. (2) is common and is why the >>replacement strategy is so important. > >I defined collision somewhere in this thread but it is the same as (1): > >from code of DarkSight which is comparable with next.c in Crafty >/********************/ > > case HASH_MOVE: > if( a tt_move is provided ) > { > tree->stats.hashkey_requests++; > if( provided tt_move is valid move ) > return tt_move; > else > tree->stats.hashkey_collisions++; > } > >/********************/ > >When I search from the starting position I get: > tree->stats.hashkey_collisions = 34 > tree->stats.hashkey_requests = 38503 > >Or to give the complete output... > >nodes searched-> 4651507 >qnodes/nodes_searched-> 0.24 >capture moves-> 0 >evaluations done-> 4150454 >first fail highs-> 220020 >fail highs-> 257405 >move-ordering: 85.48 >NULL-move fail-highs-> 903676 >tt_probes-> 1367771 >tt_hits-> 139286 >tt hit-ratio: 10.18 >TT overwrites-> 87645 > number of LOWERbounds-> 257405 > number of EXACTbounds-> 499 > number of UPPERbounds-> 115898 >hashkey collisions: 34 / 38503 = (0.0009) >ptt_probes-> 4150454 >ptt_hits-> 3627474 >ptt hit-ratio: 87.40 >PTT overwrites-> 481427 >PTT key collisions-> 82819 >Futility Prunings-> 287703 >EXTENSIONS: > Check Ext: 39065 > Mate Threat Ext: 27 > Single Reply Ext: 0 > Pushed Pawn Ext: 1086 > Recapture Ext: 31824 > Singular Ext: 0 >captures: 374765 >normals : 228993 >norm/caps: 0.61 Sorry, forgot to mention it is for a 10 ply search... Renze
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