Author: Uri Blass
Date: 04:57:16 12/10/05
Go up one level in this thread
On December 10, 2005 at 05:24:19, Vasik Rajlich wrote: >On December 09, 2005 at 15:24:03, Uri Blass wrote: > >>On December 09, 2005 at 14:52:41, Vasik Rajlich wrote: >> >>>On December 09, 2005 at 11:50:42, William Penn wrote: >>> >>>>Rybka's analysis is fairly short to begin with, compared to most other engines. >>>>It reaches its maximum after a few seconds, then it decreases at longer times. >>>>For example here's an analysis of a position in infinite mode using the Shredder >>>>Classic GUI. After 3 hours it is already showing a decrease of move information, >>>>which decreases even further after 10 hours. The specific position doesn't >>>>matter. I see this same pattern when analyzing any position for a long time. >>>> >>>>Engine: Rybka 1.0 Beta 32-bit (704 MB) by Vasik Rajlich >>>>12.01 0:03 +1.35 32.h4 g4 33.h5 Qf8 34.Qe2 Nb4 35.Rh4 Qe8 36.Ne3 (300.979) >>>>87 >>>>13.01 0:06 +1.37 32.h4 g4 33.h5 Qf8 34.Qe2 Nb4 35.Rh4 Qe8 36.Ne3 Qe6 >>>>(552.306) 90 >>>>14.01 0:15 +1.36 32.h4 g4 33.h5 Qf8 34.Qe2 Nb4 35.h6 Qf7 36.Qd2 Qe6 >>>>(1.362.839) 90 >>>>15.01 2:02 +1.34 32.h4 Qf8 33.hxg5 Rxg5 34.Qf3 Nc7 35.Rh5 Ne6 36.Rxg5 fxg5 >>>>(9.586.923) 80 >>>>16.01 3:01 +1.31 32.h4 Qf8 33.hxg5 Rxg5 34.Qf3 Nc7 35.Rh5 Ne6 36.Rxg5 fxg5 >>>>(14.741.441) 83 >>>>17.01 5:30 +1.27 32.h4 Qf8 33.hxg5 Rxg5 34.Qf3 Nc7 35.Rh5 Qg8 36.Rh4 Ne6 >>>>(27.355.485) 84 >>>>18.01 10:34 +1.19 32.h4 Qf8 33.hxg5 Rxg5 34.Qf3 Nc7 35.Rh5 Qg8 36.Rh4 Rg6 >>>>(52.200.357) 84 >>>>19.01 18:28 +1.25 32.h4 Qf8 33.hxg5 Rxg5 34.Qf3 Nc7 35.Rh5 Qg8 36.Rh4 Rg6 >>>>(90.818.525) 83 >>>>20.01 42:12 +1.13 32.h4 Qf8 33.hxg5 Rxg5 34.Qf3 Nc7 35.Rh5 Qg8 36.Rah1 Ne6 >>>>(200.052.005) 80 >>>>21.01 92:04 +1.18 32.h4 Qf8 33.hxg5 Rxg5 34.Qf3 Nc7 35.Rh5 Qg8 36.Rah1 Ne6 >>>>(427.366.814) 79 >>>>22.01 174:11 +1.14 32.h4 Qf8 33.hxg5 Rxg5 34.Qf3 Nc7 (789.072.165) 77 >>>>23.01 634:58 +1.24 32.h4 Qf8 33.hxg5 (2.860.235.585) 76 >>>> >>>>WP >>> >>>This is intentional and can _very_ easily be fixed. Please send me an email if >>>you have a strong opinion about the matter. >>> >>>In my opinion, other engines talk too much. The ends of the PVs tend to be >>>pretty silly. >>> >>>Vas >> >>I think that they do not talk enough. >> >>I think that it is productive to have an option to see more for correspondence >>games like hash moves that you already remember at small depth for every move. >> >>I will be happy if rybka can write them to a text file. >>The point is that one problem in analysis is that a program may suggest line >>1.xx yy after many hours of search and you may need hours to see the reason that >>it rejected 1.xx zz because 1.xx zz is not the pv line >> >>If the program can print to a text file the first move that it tries in the >>first 3 plies then it may be productive. >> >>Example in the opening position suppose the pv is 1.e4 e5 2.Nf3 Nf6 3,Nxe5 >> >>I would like to see in text file something like >>1)the following 19 lines for depth 2 >>1.d4 d5 >>1.c4 e5 >>... >>2)the following 19 lines for depth 3 >>1.e4 a6 2.d4 >>1.e4 a5 2.d4 >>... >> >>If I do not see it then I may need a long analysis to understand why the program >>rejected 1.d4 for white or may need a long time to understand why the program >>rejected 1.e4 a6 for black >> >>Note that it may be productive also to have lines at bigger depth for thinking >>lines that the computer considered for a long time and if the program considered >>1.d4 d5 2.Nf3 for a long time then I would like to see the hash move after these >>moves in order to understand why it rejected 1.d4 d5 2.Nf3 for white. >> >>Uri > >Uri, > >this is a response also to your email, as well as a number of other emails I got >about this. > >In the short term, an engine can only display a PV, and this PV can only be >slightly shorter or slightly longer. This doesn't give the engine programmer >much leeway, and I think we all agree that a long single search isn't a very >useful use of many hours of computer time. I do not agree here. many hours of computer time may be useful because the program may find a move that it does not find in a different way or find a win that it does not find in a different way(and knowing that there is a win in some position can be productive for analysis). The point is that a similiar win may be available in a different line and if you do not understand the reason that the program shows a winning score you may miss the second win in analysis. Anyway I have now changed the >behavior so that the PVs at least continue getting longer as more time is spent. Thanks this is better(note that very long pv is not very impoertant but it is important to have more than 3 plies on the pv because even the program may need a long time to find the 4th move or the 5th move of the pv so you may be unable to use short analysis to find it later). > >In the long term, we should be able to instruct a chess package to spend several >hours analyzing a position and giving us a full report. I agree There are already some >implementations of this, mostly at the GUI level, which is where they belong. In >principle, these features should be better. Here I do not agree and I think that the engine should do it. I think that better analysis should also lead to better move(otherwise it is not better analysis) If you think that different algorithm is better for analysis then it should be used also in playing games. > >Some ideas in this direction: > >1) The GUI makes a package report about the position - deep analysis of a number >of lines, as well as a number of "shootout" games together with statistics. >Everything should be as automated as possible. If automatic deep analysis of number of lines is productive(I believe that it can be productive) then it should be used also in games and the program should tell the user the intereting lines that it found. Having exact score for second best move at least in the first plies may be productive also in games(for example it may allow the program to have better time managament and play immediately when second best move lead to forced mate against itself). I agree that it may be productive if the engine respond to the user of the input that can tell it that some position is drawn but I think that in most positions the user does not know important details like that so the main advantage for the user is by fully automatic analysis and report with no conditions by the user. Uri
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