Author: Vincent Diepeveen
Date: 14:00:07 09/15/01
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On September 15, 2001 at 16:18:42, Uri Blass wrote: >On September 15, 2001 at 15:56:06, ALI MIRAFZALI wrote: > >>Although much has been said about moves like Be4 in game 2 of the second match >>with Kasparov and h5 in game 5 of the second match because of the great >>controversy that these moves have generated;the positions that happen >>after these moves are not a good comparison test for seeing if current >>commercial programs running on ordinary machines play at or beyond the level >>of deep Blue.Let me first turn my attention to the first match game 5.At move >>29 Deep blue plays29.g3? Kasparov says that after 29.Ne2 Rxe2 30.Qxe2 Qa1+ >>31.Nc1 White may be able to hold but the chances are still in Black's favor. >>Interestingly Fritz6 chooses 29.Ne2 in this position(under 3 minutes 450MHZ). >>In the same game at move 12 Deep blue plays 12.Rae1 .This is the case of moving >>the Wrong rook.In the same position Fritz6 plays Rfe1 instantly.There is no >>doubt that these positions prove that chess Knowelgde is very important for >>chess programs.Since the Hardware that the deep Blue program was running on >>was more powerful than anything commercial programs are running on even today > >The position is easy for programs with the relevant chess knowledge >but can be also solved by search for programs without chess knowedge. > >I remember from a post of the programmer of yace >that yace could find 29.Ne2 after some hours by search when >g3 failed low for kasparov's move. > >I believe that the search algorithm of Deep blue were simply >inferior than the search algorithm of the chess programs of today >(otherwise some hours of yace could be translated to some minutes > of the chess programs of today) >>;the question of the Camparison of a top commercial program like Fritz6 and >>Deep blue comes down to this question:In a series of games will positions >>that require chess knowledge for the selection of the best move occur more >>often then positions requireing computational power? From the 2 matches with >>Kasparov we can safely deduce that Deep Blue did not have much chess knowledge >>in Camparison with Todays programs.Now let us see an example for Computational >>Power.In the same game(game5 first match) at move 32 Deep Blue plays 32.f3 >>Fritz6 (450Mhz) even after ruuning for 20 minuetes plays 32.gxf4 which is worse >>than f3 because it leads to a faster loss. > >I remmeber that Genius3 on p100 could see f3 in a few hours. >I believe that finding f3 may be dpendent in the >evaluation function of the program and >I expect part of the top programs on good hardware to find >it in few minutes. > >Uri Please explain to me why f3 is better here than gxf4. I get direclty -2.xx for gxf4 but after f3 you get an endgame which is so simplistically lost that there is very little chance of ever even drawing it against a strong player as you have a pawn less! I don't see why gxf4 would be worse as this involves heavy tactical dogfights which all are real good for black, but the alternative is a technical simplistically won position! Probably Deep Blue evaluated the endgame wrong after f3. Most likely the border to play f3 nowadays is much tougher than back then. A lost endgame shredder, diep and many programs evaluate as being -5.xx soon, whereas old programs didn't come further than -1.x probably. In that case i bet nowadays commercials would directly play f3. Only objective search reveals of course at a certain time that gxf4 is that bad, that the alternative, a dead lost endgame with a piece less, where one can nullmove, is what you do. At 12 ply the score has dropped to 2.922 up for black for gxf4 still f2-f3 not found here. But i bet that the same line which made DB decide to play f3, that DIEP already saw that within a second here. We do not have the logfiles from deep blue here, so it is kind of useless to say DB is tactical strong here. I bet it sucked so much everywhere (compared to todays standards) that it took f3 within a second as it probably saw K+R+5 pawns versus K+R+B+3 pawns. So that's 3 for bishop - 2 for extra pawns is 1 pawn down. Add a very small positional score in endgame and it's 1.xx down for black there. Where diep says directly that f3 is over 3 pawns up for black. At 13 ply -2.857 for gxf4. Deep Blue simply sucked in endgame that it played f3, that's the logical conclusion. Nothing else than that.
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