Author: Uri Blass
Date: 07:53:38 03/17/02
Go up one level in this thread
On March 17, 2002 at 09:17:07, Christophe Theron wrote: >On March 17, 2002 at 02:13:22, Uri Blass wrote: > >>On March 16, 2002 at 22:29:26, Christophe Theron wrote: >> >>>On March 16, 2002 at 15:01:04, Uri Blass wrote: >>> >>>>On March 16, 2002 at 14:34:13, Jorge Pichard wrote: >>>> >>>>>On March 16, 2002 at 14:26:20, Jorge Pichard wrote: >>>>> >>>>>>In the first game Chess Tiger 14.9 was playing without using its Turbo Mode, in >>>>>>which it enables it to think on its opponent time to move. Now I activated Turbo >>>>>>Mode, but I am still playing Using my handspring at 32 Mhz without using >>>>>>Afterburner or Fastcpu. This time the Tiger was hungry and decided to grab a >>>>>>Gaviota for lunch. >>>>> >>>>>PS: Gaviota is playing the ending terrible, but nextgame I will continue vs Gnu >>>>>Chess v5.02 Est rating of 2225. >>>> >>>>Some details: >>>> >>>>Gaviota is estimated to have rating of 2170 when GNU chess5.03 is estimated to >>>>have rating of 2150 >>>>see http://f11.parsimony.net/forum16635/messages/23352.htm >>>> >>>>I do not know GNUchess5.02 but I doubt if it is better than Gaviota. >>>> >>>>Gnu chess played in the 3th division based on the history pages of Leo when >>>>gaviota scored clearly better than GNUchess. >>>> >>>>I admit that it was not GNUchess5.02 but I do not know if there is a big >>>>difference between 5.00 and 5.02 >>>> >>>> >>>> >>>>I think that it may be more interesting to see programs of CCC memebers and not >>>>GNUchess. >>>> >>>>possible candidate is Averno >>>> >>>>The author of faile also posted in the past(faile is clearly weaker than >>>>gaviota) >>>> >>>>My program may be also a candidate >>>> >>>>Today I believe that it is only in similar level to faile but I plan to do it >>>>stronger and it is going to be available in april. >>>> >>>>Uri >>> >>> >>> >>>It is interesting to see the progress of somebody who has been suggesting >>>improvements to programmers for a long time, and has eventually decided to try >>>them himself. >>> >>>I'm glad to see that you are writing your own chess program. I'm sure it will >>>have some unique features, and that's good. I would recommend you to reinvent >>>the wheel and not create yet another Crafty clone. It will not be a waste of >>>time. It is how things were in the eighties, and it was a great time for >>>computer chess. >>> >>>My best wishes to... Huh... Have you chosen a name for your chess program? >>> >>> >>> >>> Christophe >> >> >>Movei is the name of it. >> >>The latest tested version has only a piece square table evaluation with no book >>and no hash table. >> >>The piece square table is only changed in the endgame. > > >That's good enough as a first step. You can build a reasonably strong chess >program with PSTs. It gives you a reasonably good evaluation (assumig your PSTs >are OK) and you can focus earlier on most important things. I think that evaluating pawn structure is also important and can give my program more than 50 elo improvement. I saw often in games against gnu chess that my program had problems with it's pawn structure. > > > > >>It can be improved by better order of moves and it can be also improved by >>better extension and pruning rules(it is using only some futility pruning today >>and it does not use partial extensions) > > >Chess Tiger does not use fractional extensions either. I just use more detailed >rules for extensions and I decide to extend or not. That's 1 or 0. I suspect that it may be a question of definition. Suppose you have 2 sets of moves that you may extend A and B. suppose you always extend 1 ply when you see a move from A suppose also that you always extend 1 ply when you see a move from set B and the total number of moves from set B in the line that you search is divisble by 3 You can say that you always extend 1 ply or 0 plies but it is still the same as fractional extensions (1/3 ply for moves from set B and 1 ply for move for moves from set A). I think to do it as only 1 or 0 or -1 but the number is going to be based on fractional extensions. Today it is only 1 or 0 and the 1 is not based on fractional extensions. > > > > >> but inspite of all the problems the >>latest version could beat Faile with no book 6-4 in a match(time control was 1 >>minute/40 moves,2 minutes/40 moves...5 minutes/40 moves) >> >>It also lost 8.5-1.5 in a match against GNUchess5.03 in the same conditions. >>hardware was one pIII800. >> >>I believe that Faile and Gnuchess used hash tables in the matches(I told them no >>instruction about it but usually programs with hash tables use some hash tables >>by the default option) > > >Some advices for you: > >1) play fast games, manually, preferably on slow hardware. So the mistakes of >your program do not get hidden in very long PVs and you can more easily >understand what went wrong. Most of the games that I play are fast games. I also use test suites for testing changes that I do in search rules. > >2) Select an opponent only slightly stronger than your program. If your opponent >is too strong you learn almost nothing because both your evaluation and search >get badly beaten. You are just disgusted by the result and do not know what to >do. When you have improved, change to a stronger opponent. I do it. > >3) You'll soon discover that whatever you add in your evaluation, if your >opponent oursearches you there is nothing you can do: you lose. You will >probably have to spend months or even years improving your search algorithms in >order to avoid this. That's why I think that a PST program is OK to start with. >Don't make the mistake to try to add special cases in your evaluation in order >to cover your search's deficiencies. If you want you can add terms to evaluate >the tactical pressure on each side (couting the number of attacks for example), >but these terms must be kept general. Don't add code like "if black rook in a8 >and black king in e8 and white knight on c7 then add penalty to black score". >That does not work. > >4) Don't try to fix a weakness as soon as you discover it. Just say "that's >life". Fix it only if it happens over and over again. Generally, start by fixing >the most obvious and big mistakes. Don't try to stuff in high level knowledge >too early in your developpement. You can't run if you do not even know how to >walk. This point is the reason why I believe that being a very strong chess >player is a handicap for a chess programmer (at least in the begining). I think that knowledge in the search is more important then knowledge in the evaluation so I am not going to do it in the near future. > >5) Make a backup of your sources at least every day. I am going to do it but not every day but only after every significant change in my source code or significant improvement. Uri
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