Author: Miguel A. Ballicora
Date: 13:58:30 05/07/02
Go up one level in this thread
On May 07, 2002 at 13:53:20, Uri Blass wrote: >On May 07, 2002 at 13:19:53, Miguel A. Ballicora wrote: > >>On May 07, 2002 at 12:34:57, Uri Blass wrote: >> >>>On May 07, 2002 at 11:29:40, Miguel A. Ballicora wrote: >>> >>>>On May 07, 2002 at 02:29:26, Uri Blass wrote: >>>> >>>>>On May 06, 2002 at 22:31:28, Christophe Theron wrote: >>>>> >>>>>>On May 06, 2002 at 19:45:22, Uri Blass wrote: >>>>>> >>>>>>>On May 06, 2002 at 18:06:47, Christophe Theron wrote: >>>>>>> >>>>>>>>On May 06, 2002 at 15:34:01, Amir Ban wrote: >>>>>>>> >>>>>>>>>On May 05, 2002 at 19:58:09, Christophe Theron wrote: >>>>>>>>> >>>>>>>>>> >>>>>>>>>>"Knowledge" in the sense of positional evaluation (that's what most people think >>>>>>>>>>about when they talk about knowledge) makes for 10% of the strength of a chess >>>>>>>>>>program. >>>>>>>>>> >>>>>>>>>>Chess is 90% about tactics (which is a concept close to "search"). >>>>>>>>>> >>>>>>>>> >>>>>>>>>Before strongly disagreeing (as I guess I will), what does this mean ? >>>>>>>>> >>>>>>>>>If I freeze my search engine and work only to improve the evaluation, how much >>>>>>>>>do you expect the total strength to improve ? Is it limited ? >>>>>>>> >>>>>>>> >>>>>>>>I expect the strength of your engine to improve, but not much in regard to the >>>>>>>>energy invested. Because you are going to focus your efforts on an area that >>>>>>>>does not have the biggest potential in strength. >>>>>>>> >>>>>>>>On the other hand people will love it more and more because it will have a much >>>>>>>>better playing style. >>>>>>>> >>>>>>>>People can forgive gross tactical blunders, but not slight positional mistakes. >>>>>>>>Go figure... >>>>>>> >>>>>>>I think that people are different. >>>>>>> >>>>>>>There are people who will prefer the engine that is better in tactics and there >>>>>>>are a lot of people who are going to prefer the engine that wins without caring >>>>>>>for the reasons. >>>>>> >>>>>> >>>>>> >>>>>>That's different when your program plays against a gransmaster in a public place >>>>>>(or on the Internet). >>>>> >>>>> >>>>>comp-comp games are also interesting for many people. >>>>> >>>>>I think that programmers usually care more about comp-comp games and not about >>>>>comp-human games. >>>>> >>>>>I know that some simple ideas about time management that can be productive >>>>>against humans are not used by most of the programs. >>>>> >>>>>One of them is simply to play faster when the opponent is in time trouble. >>>>> >>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>>>>Here I'm talking about current top engines of today, naturally. >>>>>>>> >>>>>>>>Building a chess engine with a broken evaluation to demonstrate that a better >>>>>>>>evaluation could improve it tremendously is not in the spirit of my idea. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>>I understand that you are saying that it will change the style but overall >>>>>>>>>strength will not be much changed. >>>>>>>> >>>>>>>> >>>>>>>>I do not know exactly how far we will be able to go with the 10% I attribute to >>>>>>>>positional evaluation. >>>>>>>> >>>>>>>>I'm not saying it counts for nothing and that overall strength will not benefit >>>>>>>>from research in this area. >>>>>>>> >>>>>>>>I believe that the positional evaluation is the part of a chess program >>>>>>>>responsible for only 10% of the strength, and that the rest is done by the >>>>>>>>search. >>>>>>> >>>>>>>I do not understand like Amir what is the exact meaning of 10%. >>>>>>> >>>>>>>I believe that most of the amatuers can earn more rating from improvement in the >>>>>>>search rules and not from improvement in the evaluation but I also think that >>>>>>>the ratio is usually not 9:1 and I guess something like 2.5:1(I know that you >>>>>>>did not say that the ratio is 9:1 but it is a possible way to understand the >>>>>>>claim that search is responsible for 90% of the strength when evaluation is >>>>>>>responsible for 10%) >>>>>> >>>>>> >>>>>>:) >>>>>> >>>>>>You do not understand the meaning of my 10%, but you suggest that it is another >>>>>>number? >>>>>> >>>>>>So you must understand what I am talking about, somehow... >>>>> >>>>>I suggested a possible meaning for the 10% and said that by this meaning it is >>>>>another number. >>>>> >>>>>I did not say that it is your meaning and I see that it is not your meaning. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>>>I guess that it is possible to improve most of the amatuers that are 400-600 elo >>>>>>>weaker than Junior by average number of 100 elo by doing a lot of work only on >>>>>>>the evaluation when you can improve them only by average number of 250 elo by >>>>>>>doing the same amount of work on the search rules without changing the >>>>>>>evaluation. >>>>>>> >>>>>>>The total improvement from working on both things may be bigger than the sum of >>>>>>>100 and 250 because after improving the evaluation the best search rules may be >>>>>>>different. >>>>>> >>>>>> >>>>>>I don't think the proportion is measured in elo points. >>>>>> >>>>>>My unit for the 90%/10% estimation is subjective. It's something like the amount >>>>>>of reward for a given programming effort. >>>>>> >>>>>>A successful effort in search get a reward 9 times bigger than a succesful >>>>>>effort in positional evaluation. >>>>>> >>>>>>Not to say that work on positional evaluation can be ignored. >>>>>> >>>>>>I notice that some chess players tend also to agree that chess is essentially a >>>>>>matter of search (tactics). >>>>> >>>>>I agree and I also think that search is the most important thing to work about. >>>>> >>>>>I think also that evaluation and search are connected and another thing to work >>>>>about is learning from the search to change the evaluation. >>>>> >>>>>Humans do not know that fortress positions is a draw by static knowledge but >>>>>learn from their search to change their evaluation. >>>> >>>>Humans understand a fortress position by logic, certainly not by search. >>>> >>>>Regards, >>>>Miguel >>> >>>I talk about positions when humans has no previous knowledge that the position >>>is a fortress. >> >>In those positions logic could be supplemented by a little of retrograde >>analysis if the fortress is complex, but "search" play almost no part in the >>"pseudo-static" evaluation of such positions by a human. Search might be needed >>to know how to reach the fortress, but the understanding of the fortress >>comes from pure logic and "static" considerations. >>A minimum of search might be required if a complex fortress could lead to a more >>simple fortress. Generally that would like a 1-2 plies search. >>The one on the Smirin match was a fortress that a human can understand with >>almost pure logic, i.e. describing it with words rather than variations. >> >>Regards, >>Miguel > >I think that the question is what is the definition of search > >Here is the position from the game: >[D]8/1p6/4k3/5p2/pP2bP1p/2N1P1pP/1P6/6K1 b - - 0 50 > >Here are the relevant lines that humans need to search to understand that the >black king cannot goto a5-d5 >Kd5 Nxd5 >Kc5 bxc5 >Kb5 Nxb5 >Ka5 bxa5 That is not how a human player evaluates a fortress. BTW, this position is not the fortress (yet), it is after 1.. a3 2. bxa3. That is when you have the fortress. A relatively strong human player reasons like this: I have covered b5 and d5 by my knight and I have the pawns covering. a5, c5, e5, g5, g4. Black pawns cover f5 and h4. That closes a line in the middle of the board that separates my pieces from the opp. king. There is not possible break with any pawn so the pawn structure cannot be changed if white does not move. There is a passed pawn but the White king is on the square. None of the pieces are in light squares so the bishop cannot do anything. h3 is the exception but the only safe access is trhough g2 or f1 which is not possible to reach since the white king is right there. Black passed pawn wont do anything because the white king is on the square. Very important, the white king is not covering any important square on the fortress, so it is free to move in the square of the black passed pawn, hence, a zugswang is not possible. So, squares g1, g2 and f1 are ok to move back and forth and black bishop cannot even take two at the same time. I would not call this search. > >You can claim that it is no search because search is only of legal moves. > >In this case I give you another position: IMHO, this is not exactly a fortress. The white king is not forbidden to reach and attack an opposite pawn it has a free access to it. The problem is that doing so stalemates the opponent. This is in the same category as Pa6, Kb6, Bc5 vs Ka8. In fact, I think that if you have to search, it is not a fortress! Because that means that there are still "holes" that you have to cover dynamically rather than statically. Regards, Miguel > >[D]8/1pPk1K2/pP6/P7/8/8/5B2/8 w - - 0 1 > >How can humans know that it is a draw without previous knowledge? > >I think that they need to search at least lines like c8Q+ Kxc8 and learn from >searching some lines that white cannot prevent the squares d7,c8,b8,a8 from the >black king. > >Uri
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