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Subject: Re: Deep-Blue vs Kasparov, 2.game,

Author: Ed Schröder

Date: 08:23:05 05/21/00

Go up one level in this thread


On May 21, 2000 at 08:03:41, Jeremiah Penery wrote:

>On May 20, 2000 at 14:52:56, Enrique Irazoqui wrote:
>
>>On May 20, 2000 at 14:08:51, Ricardo Gibert wrote:
>>
>>>On May 20, 2000 at 13:20:47, Bruce Moreland wrote:
>>>
>>>>On May 20, 2000 at 10:04:58, Ricardo Gibert wrote:
>>>>
>>>>>On May 20, 2000 at 09:27:39, Robert Hyatt wrote:
>>>>>
>>>>>>On May 20, 2000 at 07:11:31, Terje Vagle wrote:
>>>>>>
>>>>>>>1r6/5kp1/RqQb1p1p/1p1PpP2/1Pp1B3/2P4P/6P1/5K2 b - -
>>>>>>>
>>>>>>>After 45. Ra6, Fritz suggests Qe3 for black and evaluates the position as 0,94.
>>>>>>>It does not seem to find the famous draw-line for Kasparov.
>>>>>>>10 hours analysis on PIII-600, and 28006383 KN evaluated
>>>>>>>
>>>>>>>Does any other program find the draw-line?
>>>>>>>
>>>>>>>
>>>>>>>Regards
>>>>>>>
>>>>>>>
>>>>>>>Terje
>>>>>>
>>>>>>The draw is somewhere around 60 plies deep, total.  I don't think anyone is
>>>>>>going to find that.
>>>>>
>>>>>60 plies? No way. More like half that. A lot of humans have no trouble
>>>>>calculating the draw to the end. I found it myself without any assistance of any
>>>>>kind. The only thing difficult about that draw is the psychological barrier.
>>>>>This Kaspy failed to overcome as we all know.
>>>>>
>>>>>As for computer programs, judging from the Chris Janeke post, commercial
>>>>>programs have no trouble finding the draw with a 5 ply headstart. If it were
>>>>>really 60 plies, I don't see how that would be possible.
>>>>
>>>>Oh yeah?  You'd see the part that goes h4 h5?  It's not that easy.  I helped
>>>>analyze this with a GM and an IM the day it happened, and they spent hours
>>>>trying to prove that there was a win.
>>>
>>>Yeah. I found h4 too and I remember the only reply I considered was h5.
>>
>>Is this the drawing line? The evaluation of Fritz 6b is not 0.00, but it's
>>getting there.
>>
>>Enrique
>>
>>Deep Blue - Kasparov,G
>>1r6/5kp1/RqQb1p1p/1p1PpP2/1Pp1B3/2P4P/6P1/5K2 b - - 0 1
>>
>>Analysis by Fritz 6:
>>
>>45...Qxc6--
>>  ±  (0.72)   Depth: 1/3   00:00:00
>>45...Qxc6--
>>  ±  (0.72)   Depth: 1/6   00:00:00
>>45...Qxc6 46.dxc6 Bc7
>>  ²  (0.47)   Depth: 2/7   00:00:00
>>45...Qxc6 46.dxc6 Bc7 47.Ra7
>>  ²  (0.62)   Depth: 3/10   00:00:00
>>45...Qxc6 46.dxc6 Bc7 47.Ra7 Rc8
>>  ²  (0.59)   Depth: 4/10   00:00:00  1kN
>>45...Qxc6 46.dxc6 Bc7 47.Ra7 Rc8 48.g3
>>  ²  (0.69)   Depth: 5/12   00:00:00  3kN
>>45...Qxc6--
>>  ±  (1.00)   Depth: 6/16   00:00:00  8kN
>>45...Qxc6-- 46.dxc6 Be7 47.Bd5+ Ke8 48.c7 Rc8 49.Ra7
>>  ±  (1.12)   Depth: 6/16   00:00:00  11kN
>>45...Qxc6 46.dxc6 Bc7 47.Ra7 Rc8 48.Rb7 Ke7 49.Rxb5
>>  ±  (1.22)   Depth: 7/18   00:00:00  31kN
>>45...Qxc6 46.dxc6 Bc7 47.Ra7 Rc8 48.Rb7 Ke7 49.Ke2 Kd6 50.Rxb5
>>  ±  (1.28)   Depth: 8/16   00:00:00  59kN
>>45...Qxc6 46.dxc6 Rd8 47.Ra7+ Kf8 48.Rb7 Rb8 49.Rd7
>>  ±  (1.37)   Depth: 9/18   00:00:00  131kN
>>45...Qxc6 46.dxc6 Kf8 47.Ra7 Rc8 48.Rb7 Ra8
>>  +-  (1.44)   Depth: 10/21   00:00:00  309kN
>>45...Qxc6 46.dxc6 Kf8 47.Ra7 Rc8 48.Rb7 Ra8
>>  +-  (1.44)   Depth: 11/22   00:00:01  517kN
>>45...Qxc6 46.dxc6 Kf8 47.Ra7 Rc8 48.Rb7 h5 49.Rxb5 Ke7 50.Bd5
>>  +-  (1.62)   Depth: 12/24   00:00:05  2353kN
>>45...Qxc6 46.dxc6 Kf8 47.Ra7 Rc8 48.Rb7 Ke8 49.Rxg7 Ra8 50.c7
>>  +-  (1.72)   Depth: 13/27   00:00:08  4066kN
>>45...Qxc6 46.dxc6 Kf8 47.Ra7 Rc8 48.Rb7 h5 49.Rxb5 Ke7
>>  +-  (1.72)   Depth: 14/26   00:00:14  7078kN
>>45...Qxc6 46.dxc6 Kf8 47.Ra7 Rc8 48.Rb7 h5 49.Rxb5 Ke7 50.Ra5
>>  +-  (1.75)   Depth: 15/28   00:00:26  12926kN
>>45...Qe3!
>>  +-  (1.72)   Depth: 15/41   00:01:33  43976kN
>>45...Qe3! 46.Qd7+ Kg8 47.Qxd6 Rf8 48.Qe6+ Kh7 49.Bf3 Qc1+ 50.Kf2
>>  ±  (1.25)   Depth: 15/41   00:02:03  57808kN
>>45...Qe3 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2
>>  +-  (1.53)   Depth: 16/42   00:05:13  146128kN
>>45...Qe3 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2
>>  ±  (1.28)   Depth: 17/46   00:13:16  369407kN
>>45...Qe3 46.Qxd6 Re8 47.h4 h5 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2
>>  ±  (1.16)   Depth: 18/46   00:32:34  906397kN
>>
>>(P600E/202MB, Cadaqués 20.05.2000)
>
>Well, this is what Ed gives on the Rebel pages:
>
>"Analysing this with Rebel we tried to find out the longest defense till the
>draw (repetition) would be found. Well it is at least 36 plies. Even for DB
>super machine that's too much.
>
> The line goes like this: 45.Ra6? Qe3! 46.Qxd6 Re8! 47.h4! h5! 48.Bf3 Qc1+
>49.Kf2 Qd2+ 50.Be2 Qf4+ 51.Kg1 Qe3+ 52.Kh2 Qf4+ 53.Kh3 Qxf5+ 54.Kh2 Qf4+ 55.Kg1
>Qe3+ 56.Kf1 Qc1+ 57.Kf2 Qf4+ 58.Ke1 Qc1+ 59.Bd1 Qxc3+ 60.Kf1 Qc1! 61.Ke2 Qb2+
>62.Kf1 Qc1
>
>Note 60..Qc1!
>
>It's a (quiet) non checking move. Perhaps the reason why no program can find
>45..Qe3 with a draw score?"
>
>With some version of Crafty a while back, I let it run for a week or two on my
>machine to see if it could find the draw.  It followed Ed's line for a while (up
>to ply 20 or so), and the evaluation actually dropped to 0.00 at one point.
>Unfortunately, it could not see 60. ...Qc1!! and thought it could find a way out
>of the perpetual.  The score went back up at about ply 21, and continued to rise
>through about 23, where I stopped it.  It was back to +1.xx.  I don't think any
>program is capable of finding the entire correct line here.  Just as Ed says, I
>think it's because of the non-checking move 60. ...Qc1!! that gets pruned this
>deeply in the tree.
>
>Jeremiah

You could try to start the analysis (for another week) starting with
48..Qc1+ (skipping the first non-quiet moves) till the program sees
the drwaw. Then you really get the picture how hard this position is.

:)

Ed



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