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Subject: Re: Position for Endgame Tablebase programs

Author: Robert Hyatt

Date: 06:43:20 09/23/99

Go up one level in this thread


On September 23, 1999 at 09:24:43, Wayne Lowrance wrote:

>On September 22, 1999 at 22:54:07, Robert Hyatt wrote:
>
>>On September 22, 1999 at 20:25:56, Howard Exner wrote:
>>
>>>On September 22, 1999 at 13:42:26, Robert Hyatt wrote:
>>>
>>>>On September 22, 1999 at 13:40:37, Robert Hyatt wrote:
>>>>
>>>>>On September 22, 1999 at 11:46:29, Howard Exner wrote:
>>>>>
>>>>>>Do any of the programs with endgame tablebases solve this position?
>>>>>>
>>>>>>8/6Bp/6p1/2k1p3/4PPP1/1pb4P/8/2K5 b - - id Pos 111 - ECM98H.EPD; bm b3b2
>>>>>>
>>>>>>It looks too difficult for non tablebase programs.
>>>>>
>>>>>
>>>>>Crafty solves it, but it takes longer than I would like to see...  11 minutes.
>>>>>
>>>>>here is the output:  (quad xeon with all the 5 piece ending databases).
>>>>>
>>>>>               15->   1:46  -0.09   1. ... Kd6 2. Bf8+ Ke6 3. f5+ Kf6 4.
>>>>>                                    Kb1 Bd4 5. Ba3 h6 6. Bb2 h5 7. Bxd4
>>>>>                                    exd4 8. Kb2 hxg4 9. hxg4 d3 10. Kxb3
>>>>>                                    d2 11. Kc2
>>>>>               16     2:21  -0.17   1. ... Kd6 2. Bf8+ Ke6 3. f5+ gxf5
>>>>>                                    4. gxf5+ Kf6 5. Bc5 h5 6. Kb1 Kf7 7.
>>>>>                                    Ba3 Kf6 8. Kc1 h4 9. Bb2 Be1 10. Kd1
>>>>>                                    Bf2
>>>>>         (3)   16->   4:07  -0.17   1. ... Kd6 2. Bf8+ Ke6 3. f5+ gxf5
>>>>>                                    4. gxf5+ Kf6 5. Bc5 h5 6. Kb1 Kf7 7.
>>>>>                                    Ba3 Kf6 8. Kc1 h4 9. Bb2 Be1 10. Kd1
>>>>>                                    Bf2
>>>>>         (2)   17     6:09  -0.26   1. ... Kd6 2. Bf8+ Ke6 3. f5+ Kf6 4.
>>>>>                                    Ba3 Bd4 5. Kb1 Bc3 6. g5+ Kf7 7. f6
>>>>>                                    Bd2 8. Bc1 <HT>
>>>>>               17    11:26   0.00   1. ... b2+ 2. Kc2 exf4 3. Bxc3 f3 4.
>>>>>                                    Be1 Kd4 5. Bf2+ Kxe4 6. Ba7 Kf4 7.
>>>>>                                    Bf2 Ke4
>>>>>         (4)   17->  11:42   0.00   1. ... b2+ 2. Kc2 exf4 3. Bxc3 f3 4.
>>>>>                                    Be1 Kd4 5. Bf2+ Kxe4 6. Ba7 Kf4 7.
>>>>>                                    Bf2 Ke4
>>>>>
>>>>>Don't know whether it will fail high at 18 or not, however...
>>>>
>>>>
>>>>depth 18 analysis:
>>>>
>>>>         (3)   18    13:55   0.31   1. ... b2+ 2. Kc2 exf4 3. Bxc3 f3 4.
>>>>                                    Be1 Kd4 5. Bf2+ Kxe4 6. Ba7 b1=Q+ 7.
>>>>                                    Kxb1 Kd3 8. h4 Ke2 9. h5 gxh5 10. gxh5
>>>>                                    f2 11. Bxf2 Kxf2 12. Kc2 Ke3
>>>
>>>I tried this on CM6000 and Rebel 10c but stopped after 30 minutes(this
>>>on an AMD 233). The 11 minutes looks impressive to me. In your final analysis
>>>on move number 9 rather than capturing with gxh5 the winning move is g5,
>>>so that the black king can capture both of white's pawns. However in an actual
>>>game Crafty would no doubt see that when it reached that point in the game.
>>>
>>>My guess is that we won't see to many people posting that program X
>>>finds this one. Hope I'm wrong in this guess.
>>>
>>>Now I'm also wondering if tablebases will help here as after the initial
>>>exchanges there remain two pawns each on the king's side?
>>
>>
>>It was definitely probing tablebases during the search.  The disk was very
>>active due to the captures...
>
>Yes, Hiarcs was probing table bases during its search as well. Hiarcs found the
>solution at the 21:04 minute mark and made the move shortly there after. The
>Table Base print out that followed the Hiarcs search listing was:
>
>=+ (-0.26) depth 13/30 00:21:04 72203kn, tb=12


what does "tb=12" mean?  My program did over 60,000 probes.  If that means only
12 were done, something is not done right in Hiarcs...



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