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Subject: Re: New Tough Endgame Test Suite - And note to Ed

Author: Ed Schröder

Date: 08:18:58 05/28/00

Go up one level in this thread


On May 28, 2000 at 04:17:41, Jeremiah Penery wrote:

>On May 28, 2000 at 02:37:33, Ed Schröder wrote:
>
>>On May 28, 2000 at 00:38:15, Eelco de Groot wrote:
>>
>>>Can White actually promote the g-pawn?
>>
>>I am not sure if Kg3 is winning. On the other hand if Capablanca
>>say so. The latest engine running under ECTOOL6 (beta) find Kg3
>>much quicker. Don't ask me why as I can't remember to have made
>>any changes here. But perhaps it is search related and here a lot
>>has changed.
>>
>>00:00  08.01  0.51  1.Ke2 Rxc3 2.Rd7 Rc2+ 3.Kd3 Ra2 4.Rxd5 Rxa4 5.Rxf5
>>00:01  09.00  0.51  1.Ke2 Rxc3 2.Rd7 Rc2+ 3.Kd3 Ra2 4.Rxd5 Rxa4 5.Rxf5+ Kg7
>>00:02  10.00  0.39  1.Ke2 Rxc3 2.Rd7 Ra3 3.Rxd5 Rxa4 4.Rxf5+ Kg7 5.Rd5+ c6
>>00:06  11.00  0.40  1.Ke2 Rxc3 2.Rd7 c6 3.Rxa7 Rc4 4.a5 bxa5 5.Kd3+ a4 6.Ke3
>>00:17  12.00  0.32  1.Ke2 Rxc3 2.Rd7 c6 3.Rxa7 Rc4 4.a5 bxa5 5.Ke3 a4 6.Kd3 c5
>>00:45  13.00  0.31  1.Ke2 Rxc3 2.Rd7 c6
>>02:00  14.00  0.31  1.Ke2 Rxc3 2.Rd7
>>03:16  14.02  0.38  1.Kg3 Rxc3+ 2.Kh4 Ra3 3.g6 Rxa4 4.Kg5 Rc4 5.Rf7+
>>07:48  15.00  0.35  1.Kg3 Kg8 2.Rd7 Rxc3+ 3.Kh4 Rf3 4.g6 Rxf4+ 5.Kg5 Re4 6.Rxd5
>>19:48  16.00  0.73  1.Kg3 Kg8 2.Rd7 Rxc3+ 3.Kh4 Rf3 4.g6 Rxf4+ 5.Kg5 Re4 6.Rxd5
>>c5 7.dxc5 bxc5
>>
>>Tested while reading CCC on a Athlon 600 and 60 Mb hash.
>
>Here's my last output from a slightly modified Crafty 17.10:
>
>19   140:05   1.42   1. Kg3 Rxc3+ 2. Kh4 a6 3. g6 b5 4.
>                     axb5 axb5 5. Rf7+ Kg8 6. Rxf5 Kg7 7.
>                     Rxd5 Kxg6 8. Rxb5 Rc4 9. Rd5 c6 10.
>                     Rd8 Kf5 11. Rf8+ Ke4
>
>It liked Kg3 from iteration 15, with an ever-increasing score.
>
>On another note, in response to your (Ed's) post about the difficulty of "The DB
>position", where he said something like "To truly appreciate the difficulty of
>this position, search after all the quiet moves, and see if your program can
>find 60. ...Qc1.  Here's what the same Crafty finds after a long time:
>
>(The move numbers should begin with ...48 here, so 60 should be where 13 is.)
>20-> 887:24  -0.87   1. ... Qc1+ 2. Kf2 Qd2+ 3. Be2 Qf4+
>                     4. Kg1 Qe3+ 5. Kh2 Qf4+ 6. Kh3 Qxf5+
>                     7. Kh2 Qf4+ 8. Kg1 Qc1+ 9. Kf2 Qf4+
>                     10. Ke1 Qc1+ 11. Bd1 Qxc3+ 12. Kf1
>                     Qc1 13. Ra7+ Kg6 14. Ke2 c3 15. Qd7
>21   1307:00  1/30   1. ... Qc1+
>
>21   1654:58     ++   1. ... Qc1+!!
>21   2223:06   0.00   1. ... Qc1+ 2. Kf2 Qd2+ 3. Kg3 Qe1+
>                     4. Kh3 Qh1+ 5. Kg3 Qe1+
>21-> 2223:06   0.00   1. ... Qc1+ 2. Kf2 Qd2+ 3. Kg3 Qe1+
>                     4. Kh3 Qh1+ 5. Kg3 Qe1+
>
>I suppose since it found some sort of draw, it just outputted a short one, for
>some reason.  I rather don't like that, so I moved forward a few more moves from
>Ed's given line, and I got:
>
>(This should begin with move ...53.)
>17->  77:30  -0.09   6. ... Qxf5+ 7. Kh2 Qf4+ 8. Kg1 Qe3+
>                     9. Kf1 Qc1+ 10. Kf2 Qf4+ 11. Ke1 Qc1+
>                     12. Bd1 Qxc3+ 13. Kf1 Qc1 14. Ra7+
>                     Kg6 15. Ke2 c3 16. Qd7
>18   128:48   0.00   6. ... Qxf5+ 7. Kh2 Qf4+ 8. Kg1 Qe3+
>                     9. Kf1 Qc1+ 10. Kf2 Qf4+ 11. Ke1 Qc1+
>                     12. Bd1 Qxc3+ 13. Kf1 Qc1 14. Ra7+
>                     Kg6 15. Ke2 Qb2+ 16. Kf1 Qc1
>18-> 134:45   0.00   6. ... Qxf5+ 7. Kh2 Qf4+ 8. Kg1 Qe3+
>                     9. Kf1 Qc1+ 10. Kf2 Qf4+ 11. Ke1 Qc1+
>                     12. Bd1 Qxc3+ 13. Kf1 Qc1 14. Ra7+
>                     Kg6 15. Ke2 Qb2+ 16. Kf1 Qc1
>
>So it does eventually find Qc1, and it extends Ed's line by 2 moves by playing
>Ra7+ - this pushes the draw out even further. :-/

Wow so the draw is even deeper. Thanks for the (long) investigation.

Ed

>Jeremiah



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