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Subject: Re: The opening book is extreamly important for a chess engine.....Jorge....

Author: Vasik Rajlich

Date: 03:43:30 09/27/04

Go up one level in this thread


On September 27, 2004 at 06:41:32, Vasik Rajlich wrote:

>On September 26, 2004 at 08:38:38, Sandro Necchi wrote:
>
>>On September 26, 2004 at 07:58:24, Vasik Rajlich wrote:
>>
>>>On September 25, 2004 at 15:16:52, Sandro Necchi wrote:
>>>
>>>>On September 25, 2004 at 14:52:42, Vasik Rajlich wrote:
>>>>
>>>>>On September 25, 2004 at 11:19:52, Sandro Necchi wrote:
>>>>>
>>>>>>On September 25, 2004 at 11:12:19, Vasik Rajlich wrote:
>>>>>>
>>>>>>>On September 25, 2004 at 09:47:23, Sandro Necchi wrote:
>>>>>>>
>>>>>>>>On September 25, 2004 at 03:57:30, Uri Blass wrote:
>>>>>>>>
>>>>>>>>>On September 25, 2004 at 01:56:37, Sandro Necchi wrote:
>>>>>>>>>
>>>>>>>>>>On September 24, 2004 at 13:05:52, Sandro Necchi wrote:
>>>>>>>>>>
>>>>>>>>>>>On September 24, 2004 at 12:09:00, Vasik Rajlich wrote:
>>>>>>>>>>>
>>>>>>>>>>>>On September 23, 2004 at 13:31:55, Sandro Necchi wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>>On September 23, 2004 at 01:44:08, Uri Blass wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>>On September 23, 2004 at 01:31:37, Sandro Necchi wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>On September 22, 2004 at 06:58:33, martin fierz wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>On September 22, 2004 at 05:56:02, Vikrant Malvankar wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>It is not a benefit for a weak engine as it will also probably play weak moves
>>>>>>>>>>>>>>>>>in the middlegame which will be properly exploited by the stronger engine. Dont
>>>>>>>>>>>>>>>>>u think so.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>it's not the issue whether a strong engine will beat a weak engine. that is so
>>>>>>>>>>>>>>>>by definition :-)
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>the question is: take 2 engines of approximately equal playing strength, give
>>>>>>>>>>>>>>>>one of them a good book, and look what happens in a match.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>i believe that for 2 weak engines the difference will be larger in the match
>>>>>>>>>>>>>>>>result than for 2 strong engines.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>now we only need somebody to test this hypothesis :-)
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>cheers
>>>>>>>>>>>>>>>>  martin
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>Hi,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>I made very many tests and I can make statements on this matter:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>1. A program stronger 150 points than another will win nearly all games no
>>>>>>>>>>>>>>>matter how bad it comes out from the openings.
>>>>>>>>>>>>>>>2. The stronger the program is the most important the book is. Of course weak
>>>>>>>>>>>>>>>lines should be checked and removed to avoid loosing positions.
>>>>>>>>>>>>>>>3. The weaker the program is the less the book is important. The reason is that
>>>>>>>>>>>>>>>it will find very many positions where it does not know how to play them.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>P.N. Do not take the Shredder - Hydra example to state the opposite, because I
>>>>>>>>>>>>>>>knew we had some weak lines in the book, but for personal reasons could not work
>>>>>>>>>>>>>>>on them.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>Of course anybody can state the opposite, but my statements are supported by
>>>>>>>>>>>>>>>thousand of games and more than 100 engines/prototype testing at all level and
>>>>>>>>>>>>>>>with very many different harware.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>I have no time and williness to do deeper into these matters, so it is up to you
>>>>>>>>>>>>>>>to believe me or not.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>Sandro
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>At the very weak level books are not important because the program that get
>>>>>>>>>>>>>>better position cannot use it.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>At the very high level books are also not important because the program can find
>>>>>>>>>>>>>>better moves by itself.
>>>>>>>>>>>>>
>>>>>>>>>>>>>No, this is today totally wrong in at least 95% cases.
>>>>>>>>>>>>>
>>>>>>>>>>>>>It depends on the positions, but in some positions they should search at 64/108
>>>>>>>>>>>>>to be able to do it and I do not think any chess program is able to reach those
>>>>>>>>>>>>>depths now.
>>>>>>>>>>>>>
>>>>>>>>>>>>>I have made several tests running fast harware for more than one day and the
>>>>>>>>>>>>>moves and the evaluation they got was poor compared to real ones.
>>>>>>>>>>>>
>>>>>>>>>>>>Depends on what "real ones" means. Humans also make mistakes.
>>>>>>>>>>>
>>>>>>>>>>>Yes, but I was referring to deep analysis of a position, not games. Some times
>>>>>>>>>>>deep analysis takes days, months or even longer...otherwise is not deep...:-)
>>>>>>>>>>
>>>>>>>>>>An example:
>>>>>>>>>>
>>>>>>>>>>after 1. e4 c5 2. Nf3 d6 3. d4 cd4 4. Nd4 Nf6 5. Nc3 a6 can computers answer
>>>>>>>>>>these questions:
>>>>>>>>>>
>>>>>>>>>>1. Is this the best line for white?
>>>>>>>>>
>>>>>>>>>I guess that humans cannot answer better.
>>>>>>>>
>>>>>>>>They do...ECO volums are about 80% reliable. Even if there is still a lot of
>>>>>>>>room for improvements this does not mean that the computers will improve theory.
>>>>>>>>
>>>>>>>>Just consider what follows:
>>>>>>>>
>>>>>>>>1. Current theory is based on more than 100 years games played by many strong
>>>>>>>>players also at corrispondance chess too.
>>>>>>>>2. Top engines do not have more chess knowledge of GMs and they do not see
>>>>>>>>deeper. A program looking at 18/44 see 9 full moves as average, 22 on the best
>>>>>>>>line and maybe 4-5 on some lines which are cut early. This is not much compared
>>>>>>>>to deep analysis by GMs.
>>>>>>>>
>>>>>>>>If the programs cannot use the knowledge made by strong players they need to see
>>>>>>>>quite deeper that they can. Of course there are positions where they look ahead
>>>>>>>>is already enough and on these they are dangerous players, but these are mostly
>>>>>>>>tactical ones or where material gain is an important factor.
>>>>>>>>
>>>>>>>>Positions where a positional compensation for given material is important are
>>>>>>>>not handled well unless the look ahead can see how to get back material and or a
>>>>>>>>mate.
>>>>>>>>
>>>>>>>>Of course weak reply can make weak moves very strong, but it depends who is the
>>>>>>>>opponent...
>>>>>>>>
>>>>>>>>>
>>>>>>>>>>2. Is 2...d6 best move for black?
>>>>>>>>>
>>>>>>>>>Again I guess that humans cannot answer.
>>>>>>>>
>>>>>>>>They gave a 80% reliable answer...the future will see this percentage raise more
>>>>>>>>and more...
>>>>>>>>
>>>>>>>>>Probably 2...d6 is one of some drawing moves but I cannot be sure about it.
>>>>>>>>>
>>>>>>>>>>3. Is this line best line for black?
>>>>>>>>>>4. What is white best move at move 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
>>>>>>>>>>18, 19 and 20?
>>>>>>>>>>5. What are the best reply for black on those moves and the white best line?
>>>>>>>>>>6. How deep should a chess program need to search to give these answers?
>>>>>>>>>>
>>>>>>>>>>Uri, do you really think a chess program can give better answers (moves) than a
>>>>>>>>>>strong human player?
>>>>>>>>>
>>>>>>>>>I do not know.
>>>>>>>>>I think that in most cases they will give moves with the same quality.
>>>>>>>>>In some cases espacially in moves 11-20 they may give better moves if you give
>>>>>>>>>them a long time to analyze.
>>>>>>>>
>>>>>>>>My very many tests show that this is happening very seldom.
>>>>>>>
>>>>>>>The big question is if the engine's moves are really worse, or just different.
>>>>>>
>>>>>>Most of the time worse...a few times different.
>>>>>>
>>>>>>Most of the time worse because the horizonth effect is giving not engough
>>>>>>depth...a few times different because they do not follows rules as humans do and
>>>>>>look also moves which will be normally weak, so humans do not investigate on
>>>>>>them usually...
>>>>>>
>>>>>>Sandro
>>>>>
>>>>>In this case, a competent correspondence chess player should crush an engine
>>>>>running without human assistance.
>>>>
>>>>I agree.
>>>>
>>>>>
>>>>>IMO a lot of people don't trust computer moves, because they often look so ugly
>>>>>- but in fact those moves are actually not so weak.
>>>>
>>>>Of course not so weak, but a GM would see that they are not the best and
>>>>increase the advantage move after move...normally a GM makes at least 2 mistakes
>>>>and some minor ones in a game, but on correspondance chess it would be
>>>>different...
>>>>
>>>
>>>Yes - but sometimes the computer's move is in fact better, and the humans are
>>>wrong to override it.
>>
>>We are saying the same thing...this is a tactical move and the computer does not
>>need to look that much ahead to find this move. White position is solid, so the
>>rook can capture.
>>
>>Some times novelties comes from the computers, but also from weak players that
>>play some interesting moves without understanding how good they are and the GMs
>>pick up the idea and refine them into a specific plan/home preparation.
>>
>>More than this specific move I think Gary was afraid of specific preparation by
>>the opponent.
>>
>>Normally it is better bring out novelties rather than facing the ones from the
>>opponents.
>>
>>Sandro
>
>Rxb7 is a hard move for a human to "understand". White gives up the d4 pawn,
>which is normally very important in this opening. Computers are much more
>flexible in their handling of positions than humans, they are more ready to all
>of a sudden do something completely different.
>
>Here is another example, from a previous thread here.
>

Ok hopefully with diagram:

[D] rnbq1rk1/3nbpp1/1p5p/p1Ppp3/NP1P3P/3B1N1R/P4PP1/R1BQK3 w Q - 0 13

>
>This happened in a game of mine. My opponent had prepared this, and concluded
>that black is winning here. After the game, I analyzed myself with Shredder, and
>agreed with him.
>
>In fact, the unnatural, inconsistent "computer move" 13. dxe5 is equalizing here
>for white. I simply ignored Shredder when it was suggesting it ...
>
>Vas
>
>>>
>>>Consider the following position:
>>>
>>>[Event "BGN World Chess Championship"]
>>>[Date "2000.10.10"]
>>>[Round "2"]
>>>[White "Kramnik, Vladimir"]
>>>[Black "Kasparov, Garry"]
>>>
>>>1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3 Bg7 7. Nf3 c5 8.
>>>Be3 Qa5 9. Qd2 Bg4 10. Rb1 a6
>>>
>>>[D] rn2k2r/1p2ppbp/p5p1/q1p5/3PP1b1/2P1BN2/P2Q1PPP/1R2KB1R w Kkq - 0 11
>>>
>>>Here Kramnik sprung a very strong novelty - the previously ignored "computer
>>>move", 11. Rxb7. Kasparov was not ready for it, and did not repeat the Gruenfeld
>>>in the rest of the match.
>>>
>>>Vas
>>>
>>>>Sandro
>>>>>
>>>>>Vas
>>>>>
>>>>>>>
>>>>>>>Vas
>>>>>>>
>>>>>>>>>
>>>>>>>>>Uri
>>>>>>>>
>>>>>>>>Sandro



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