Author: Jeremiah Penery
Date: 23:58:36 07/22/00
Go up one level in this thread
On July 22, 2000 at 22:09:36, Robert Hyatt wrote:
>On July 22, 2000 at 19:17:26, Ed Schröder wrote:
>
>>On July 22, 2000 at 16:03:59, Amir Ban wrote:
>>
>>>On July 22, 2000 at 15:32:26, Ed Schröder wrote:
>>>
>>>>On July 22, 2000 at 14:16:51, Andrew Dados wrote:
>>>>
>>>>>On July 22, 2000 at 14:11:20, Ed Schröder wrote:
>>>>>
>>>>>>On July 22, 2000 at 13:28:28, blass uri wrote:
>>>>>>
>>>>>>>Deeper blue had a positive evaluation before trading queens.
>>>>>>>
>>>>>>>The evaluation of Deeper blue was based on Deeper blue's logfile
>>>>>>>
>>>>>>>9(6) 3 T=46 34...Qxf1
>>>>>>>10(6) 2 T=130 34...Qxf1
>>>>>>>11(6) 2 T=168 34...Qxf1
>>>>>>>
>>>>>>>The evaluation when deeper blue started to ponder (hash guess Rxf1) was
>>>>>>>
>>>>>>>7 (4) -30
>>>>>>>7 (6) -66
>>>>>>>8 (6) -50
>>>>>>>9 (6) -50
>>>>>>>10 (6) -50
>>>>>>>11 (6) -48
>>>>>>>
>>>>>>>Deeper blue lost 0.5 pawn in the evaluation and the only reason that I
>>>Even if only a small part is preprocessed, the effect here is huge: half a pawn.
>>>DB played 37... Qxf1+ into an even position and woke up a move later into a
>>>half-pawn disadvantage. This means that according to its own evaluation Qxf1 is
>>>a blunder and would never have been played if not for preprocessing.
>>>
>>>DB switched from Qe2 (-21) to Qxf1+ (+2) and then learned that it's actually
>>>Qxf1+ (-48). So Qe2 was clearly better by DB evaluation.
>>>
>>>Junior evaluates Qe2 and Qxf1+ as equals.
>>>
>>>Amir
>>
>>When I run Rebel (which has no pre-processing stuff in this position) the
>>Rebel score for white goes up to from about -0.06 to +0.55 on deeper plies
>>after 34..Qe2 35.Qxe2 Bxe2 and after 34..Qxf1+ 35. Rxf1 the score remains
>>about equal, slightly worse for white (-0.15). This means a score difference
>>of 0.70 between Qe2 and Qxf1+ in favor of Qxf1+ the move played by DB
>>which makes it actually more complicated to judge if we have case here of
>>an infamous pre-processor mistake (or not) as after all the good move is
>>played (in Rebel's view of course).
>>
>>Below is the Rebel analysis, maybe you or Uri can filter out something
>>important as for me it is impossible to judge which of the moves is
>>better as this position is beyond my understanding.
>>
>>And maybe you should run Junior a bit longer and see if Qe2 in the end
>>also is refuted.
>>
>>Ed
>>
>>Rebel's log-file. Note that I have given the moves 34..Qe2 35.Qxe2 Bxe2
>>in advance to speed-up things a bit.
>>
>>[Event "?"]
>>[Site "?"]
>>[Date "1997.05.03"]
>>[Round "?"]
>>[White "Garry Kasparov"]
>>[Black "Deep Blue 2"]
>>[Result "1-0"]
>>[WhiteElo "?"]
>>[BlackElo "?"]
>>[ECO "A07"]
>>
>>1.Nf3 d5 2.g3 Bg4 3.b3 Nd7 4.Bb2 e6 5.Bg2 Ngf6 6.O-O c6 7.d3 Bd6 8.Nbd2
>>O-O 9.h3 Bh5 10.e3 h6 11.Qe1 Qa5 12.a3 Bc7 13.Nh4 g5 14.Nhf3 e5 15.e4
>>Rfe8 16.Nh2 Qb6 17.Qc1 a5 18.Re1 Bd6 19.Ndf1 dxe4 20.dxe4 Bc5 21.Ne3
>>Rad8 22.Nhf1 g4 23.hxg4 Nxg4 24.f3 Nxe3 25.Nxe3 Be7 26.Kh1 Bg5 27.Re2
>>a4 28.b4 f5 29.exf5 e4 30.f4 Bxe2 31.fxg5 Ne5 32.g6 Bf3 33.Bc3 Qb5
>>34.Qf1 Qe2 35.Qxe2 Bxe2
Here's some slightly deeper analysis I did on a slightly modified Crafty 17.11
(Most of the modifications are in search, for example it does no null-move in
iterations 1 through 6 or when the depth remaining is less than 4.)
15-> 27:42 -1.54 1. ... Ra8 2. Re1 Rad8 3. Kf2 b5 4.
Bg2 Ng4+ 5. Nxg4 hxg4 6. f6 e3+ 7.
Rxe3 Rxe3 8. Kxe3 Re8+ 9. Kf4 Re4+
10. Kf5 Bxg2
17 400:05 -1.28 1. ... b5 2. Kf2 Rd6 3. Re1 Ng4+ 4.
Bxg4 hxg4 5. Kg1 Kg8 6. Bb2 Kf8 7.
Kf1 Rd2 8. f6 Red8 9. Kg1 R8d7 10.
Be5
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