Author: JW de Kort
Date: 05:23:21 12/17/02
Go up one level in this thread
On December 17, 2002 at 08:07:02, Uri Blass wrote: >On December 17, 2002 at 07:59:21, JW de Kort wrote: > >>On December 17, 2002 at 07:53:15, Uri Blass wrote: >> >>>On December 17, 2002 at 07:30:02, JW de Kort wrote: >>> >>>>On December 17, 2002 at 07:07:46, Uri Blass wrote: >>>> >>>>>On December 17, 2002 at 06:31:50, JW de Kort wrote: >>>>> >>>>>>On December 17, 2002 at 05:45:28, Uri Blass wrote: >>>>>> >>>>>>>On December 17, 2002 at 05:34:31, JW de Kort wrote: >>>>>>> >>>>>>>>On December 17, 2002 at 05:09:31, Gian-Carlo Pascutto wrote: >>>>>>>> >>>>>>>>>On December 17, 2002 at 04:15:26, JW de Kort wrote: >>>>>>>>> >>>>>>>>>>Hi, >>>>>>>>>> >>>>>>>>>>Currently i'am using a piecelist to keep track of the locations of the pieces in >>>>>>>>>>my 0x88 based program. Iám thinking about removing this list and replacing it by >>>>>>>>>>a bitboard to keep track of the piecelocations of white pieces and black pieces. >>>>>>>>>>I'am wondering of anybody else does this (i think some one will) and if this is >>>>>>>>>>a good improvement to spees up my engine which is terrably slow. I have good >>>>>>>>>>expierences with other bitboards in my program. I already use bitboard to do the >>>>>>>>>>pawn evaluations and i'am thinkin about gradually removing the 0x88 stuff to >>>>>>>>>>replace it with bitboards >>>>>>>>>> >>>>>>>>>>any help appreciated >>>>>>>>> >>>>>>>>>Have you used a profiler to check where the program is spending most of its >>>>>>>>>time? >>>>>>>>> >>>>>>>>>-- >>>>>>>>>GCP >>>>>>>> >>>>>>>>Indeed i did. Most of its time is pend in the evualation code but that is nomal. >>>>>>> >>>>>>>I do not think that this is normal >>>>>>>Amir ban said that only 20% of the time is spent on the evaluation code of >>>>>>>Junior. >>>>>>> >>>>>>>The question is also what you define as evaluation code. >>>>>>> >>>>>>>I have arrays that are used in the evaluation and I update them when I make >>>>>>>moves. >>>>>>> >>>>>>>Should I include the time that I update the array as part of my evaluation code. >>>>>>>even if the arrays are used not only for evaluation but also for extension >>>>>>>rules? >>>>>>> >>>>>>>Uri >>>>>> >>>>>>Dear Uri, >>>>>> >>>>>>I do not dream of comparing my program to Junior. I managed to cut the time >>>>>>spend evaluating by using lazy evaluation. No my program does not do a full >>>>>>evaluation in a large number of positions. >>>>>> >>>>>>If i would do what you did i would not include the time spend updating as part >>>>>>of the time spend evaluating. >>>>>> >>>>>>Regards >>>>>> >>>>>>JWK >>>>> >>>>>By that definition today I use less than 5% of the time in evaluation. >>>>>My evaluation includes only the following factors: >>>>>1)piece square table >>>>>2)mobility when I use only the number of moves that both sides have(this >>>>>evaluation can be improved but it clearly help my program and I believe that it >>>>>is more important than knowledge about pawn structure). >>>>>3)double pawns(I use special arrays that are updated during making move for it) >>>>>4)some secret factor that is easy to evaluate for my program. >>>> >>>>I have no exact percentage but i estimate about 50% is spend evaluating. I use >>>>1) also, 2) i do not because i am afraid it is to costly to calculate but i will >>>>try it soon, 3( i also have plus a number of other pawn factors, en 4) i also >>>>have some extra features like devolpment etc. >>>> >>>> >>>> >>>> >>>> >>>> >>>>> >>>>>I believe that secret 4 is something that no program or almost no program knows >>>>>to evaluate and I do not want to lose my relative advantage. >>>> >>>>You are right about this. >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>>> >>>>>I have also secrets in my search algorithm but at the same time I also do stupid >>>>>things that no top program does(for example I do not use hash table efficientely >>>>>and I do not have some productive extensions that crafty have) so my search is >>>>>still clearly inferior to the search of the top programs. >>>>> >>>> >>>>The same goes for my program. My hashtable is not used efficiently but iam happy >>>>that is does work at all. >>>> >>>> >>>> >>>> >>>> >>>> >>>>>My program can often beat crafty in tactics but I am not going to say that >>>>>it is better than crafty in tactics inspite of the fact that it may be better >>>>>than crafty in the GCP test suite(comparison in the gcp test suite is unfair >>>>>because movei trains on this suite and I decided about changes in my search >>>>>algorithm in some cases from learning the reason that movei failed). >>>> >>>>I have not jet matches up my program agains Crafty. >>> >>>I also do not play games with it against crafty and I meant to say that it often >>>is better than crafty in test positions. >> >>Sorry, i miss understood, but never the less it is a good result that i hope to >>achieve also one day. Why don't you play Crafty? >> >> >>BTW"Is your engine available to the public? It would be nice to test my engine >>against. > >The latest version is not available but old movei is available and is clearly >better than tscp and probably slightly better than gerbil so you can use it for >testing. I will do that as soon as possible > >> >> >> >> >> >> >> >> >>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>>> >>>>>My target is of course to do it playing better but if I have some trick to make >>>>>it clearly faster in some positions without making it slower in other positions >>>>>then this trick is probably productive trick also in games(I also test in games >>>>>to verify that I did not do something bad in my search rules). >>>> >>>>Can you be more specific? >>> >>>I can give one example >>> >>>I have an array that tell me if a piece is pinned(I use that array in my move >>>generator that generates only legal moves) so there is no problem for me to >>>check if the queen of the side to move is pinned. >> >>I'am thinking about implementing something like that but in 0x88 i think it is >>very difficult. Do you use 0x88 or bitboards? > >I do not use bitboards but I also do not use 0x88. > >I use array of 64 squares. >a1 is 0 and h8 is 63. > >For every square I use a 32 bit number to store information about the directions >that a square is attacked in my attack tables(16 for white and 16 for black). > >Uri I read about something like this in a thesis by van Kervinck and i have been thinking about implementing it, but i am afraid it will be to costly soeaking in time. Could you be more specific how you implemented this?
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