Author: Vincent Diepeveen
Date: 18:24:43 02/02/01
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On February 02, 2001 at 02:14:41, Sandro Necchi wrote: So in short you prefer a 30 ply material only search with tactical extensions up to say 60 ply or so? You prefer this over a say 12 ply search of a chessprogram? >On February 01, 2001 at 09:44:28, Vincent Diepeveen wrote: > >>On February 01, 2001 at 04:11:36, Sandro Necchi wrote: >> >>>On February 01, 2001 at 03:48:09, Uri Blass wrote: >>> >>>Dear Uri, >>> >>>>On February 01, 2001 at 02:20:33, Sandro Necchi wrote: >>>> >>>> >>>><snipped> >>>>>No, maybe I did not clearly explain what I meant. I said that a friend of mine, >>>>>testing the program regardless of the opening book, said that it was 100 points >>>>>better than Fritz 6a. So it was not the book making it stronger, but the engine >>>>>being stronger. >>>> >>>>My impression about the engine is different. >>>> >>>>I used ahredder5 for a long time to analyze positions from my correspondence >>>>games when I was in theory. >>>>If the engine is 100 elo better than I expect it to find good moves in the >>>>opening without opwning book. >>> >>>I think that to expect PCs chess programs "to make theory" is wrong. The horizon >>>effect should create a lot of problems on this matter. it really depends on the >>>positions. In some program A should do better than program B and viceversa. >> >>Sorry to fall into this discussion but the word horizon effect >>is no longer valid. If you get a real small search depth like 6 or 8 ply >>then you might refer to horizon effect, but we talk about depths >>of like 13 ply and more here to start with knowing Uri that's the >>minimum depth he let the progs analyze. I'm sure Shredder at >>so many hours a move gets a bit more as 13 also. >> >>Horizon effect is no longer valid then, as that would mean that >>you assume everything is horizon effect till the game is solved by search >>which is quite hard on todays pc's > >No, I do not agree. Well, since the best move is selected by a numerical plus >compared to other moves and the programs are really selective, the depht are not >really valid because a lot of moves are discharged to reach such a dephts. So >some moves are not analized deeply enough and this would done only at high >dephts. >So to really see many moves ahead as it really needs in the early stage of a >game it takes a huge amount of time. >This situation will get better when the full search will reach 30 ply with 60 >ply selective. >I think the computer speed must be increased quite a bit to do so, so maybe in >the next 10 years or so. >I agree that a lack of knowledge would effect the search also, but generally >speaking in chess there are so many exceptions that needs to be analised deeper >to see everything clear enough to correct knowledge missing and/or wrong >evaluations. >So, my concept is the programs do not know what they know and somebody must take >a look to them to let them take the correct way. > >Sandro >> >>More valid is the term preprocessor + lack of knowledge. >> >>>> >>>>I found that shredder suggested me a stupid sacrifice and only after many hours >>>>the score went down and it converge to the theory move Re1. >>>> >>>>Here is the opening in my correspondence game against yoav dothan(I am white) >>>> >>>>1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6 5.Nc3 >>> >>>Even if this is probably the best move, I think for Shredder 5. Bd3 should be >>>better after some moves. I know that the program evaulation is better for Nc3, >>>but it is important the program position understanding after some moves... >>> >>>Qc7 6.Be2 b5 7.0-0 Bb7 >>>> >>>>I gave Shredder5 to analyze this position for a long time and it needed many >>>>hours to avoid the bad sacrifice 8.e5 >>>>It changed it's mind to Re1 that is the theory move only after many hours. >>> >>>This confirms what I said before. if the position is understood by the program >>>the program would find the correct moves easily. >>>> >>>>I analyzed 8.Re1 when there is an interesting line 8.Re1 b4 9.Nd5. >>>>I can also sacrifice a pawn by 9.Na4 >>>> >>>>I did not get a clear consequence about the sacrifices and I decided after a >>>>long think to play 8.a3 and not to sacrifice a pawn or a knight(the game >>>>continued 8...Nf6 9.Qd3 d6 10.Bg5 and it is yoav to move). >>>> >>>>One of the reason that I decided not to sacrifice is the fact that my opponent >>>>does not have to accept and I assume in my correspondence games that my opponent >>>>will probably play the best move. >>> >>>Yes, you are correct. >>>> >>>>It means that if I evaluate that b4 has 50% chance to win and 50% chance to lose >>>>my chances are smaller than 50% because I assume that my opponent will play b4 >>>>with probability of more than 50% if it wins and will not play it with >>>>probability of more than 50% if it loses. >>> >>>I agree, but what is best to play is also what will bring you to a position >>>which will suite your style or positions where you can play at your top strenght >>>and not only a general % score. >>>I understand this is not easy to explain and this is why one never stops to >>>learn... >>>> >>>>Uri >>> >>>Sandro
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