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Subject: Re: L.D.Evans-Haik,London 1978

Author: Dann Corbit

Date: 19:55:02 10/18/01

Go up one level in this thread


On October 18, 2001 at 21:01:46, Slater Wold wrote:

>On October 18, 2001 at 09:14:43, José Antônio Fabiano Mendes wrote:
>
>>      L.D.Evans-Haik,London 1978 [unusual and difficult position]
>>      [D]8/p2P3P/k7/8/8/2q5/6PK/1Q6 b
>>       "Surprisingly Black can deliver perpetual check or force stalemate."
>>    Source:"Tactical Chess Endings",by GM John Nunn,page 35
>
>Talk about a bummer..............
>
>EPD Kit revision date: 1996.04.21
>found computer opening book file [./bookc.bin].
>max threads set to 2
>hash table memory = 768M bytes.
>pawn hash table memory = 40M bytes.
>EGTB cache memory = 32M bytes.
>6 piece tablebase files found
>26330kb of RAM used for TB indices and decompression tables
>choose from 2 best moves.
>
>
>Crafty v18.12 (2 cpus)
>
>White(1): st 3600
>search time set to 3600.00.
>White(1): epdpfga drawtest.epd drawtest.out
>PFGA: EPD record: 1
>end-game phase
>              clearing hash tables
>              time surplus   0.00  time limit 60:00 (60:00)
>         nss  depth   time  score   variation (1)
>starting thread 1
>                7     0.14   6.02   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kg5 Qd2+ 6. Kh5 Qd4
>                                    7. Qg6+ Kb7 8. g4
>                7->   0.16   6.02   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kg5 Qd2+ 6. Kh5 Qd4
>                                    7. Qg6+ Kb7 8. g4
>                8     0.29   5.92   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kg5 Qe3+ 6. Kf6 Qd4+
>                                    7. Ke6 Qc4+ 8. Ke5 Qc7+ 9. Ke6 Qd8
>                8->   0.33   5.92   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kg5 Qe3+ 6. Kf6 Qd4+
>                                    7. Ke6 Qc4+ 8. Ke5 Qc7+ 9. Ke6 Qd8
>                9     0.63   5.92   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kg5 Qe3+ 6. Kf6 Qd4+
>                                    7. Ke6 Qc4+ 8. Ke5 Qc3+ 9. Kd5 Qa5+
>                                    10. Ke6 Qd8
>                9->   0.72   5.92   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kg5 Qe3+ 6. Kf6 Qd4+
>                                    7. Ke6 Qc4+ 8. Ke5 Qc3+ 9. Kd5 Qa5+
>                                    10. Ke6 Qd8
>               10     1.24   5.82   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kf3 Qc3+ 6. Kf4 Qd2+
>                                    7. Ke5 Qc3+ 8. Ke6 Qc4+ 9. Ke5 Qc5+
>                                    10. Kf4 Qd6+ 11. Kf3 Qa3+ <HT>
>               10->   1.33   5.82   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kf3 Qc3+ 6. Kf4 Qd2+
>                                    7. Ke5 Qc3+ 8. Ke6 Qc4+ 9. Ke5 Qc5+
>                                    10. Kf4 Qd6+ 11. Kf3 Qa3+ <HT>
>               11     2.30   5.82   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kf3 Qc3+ 6. Kf4 Qd2+
>                                    7. Ke5 Qc3+ 8. Ke6 Qc4+ <HT>
>               11->   2.71   5.82   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kf3 Qc3+ 6. Kf4 Qd2+
>                                    7. Ke5 Qc3+ 8. Ke6 Qc4+ <HT>
>               12     5.02   5.82   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kf3 Qc3+ 6. Kf4 Qd2+
>                                    7. Ke5 Qc3+ 8. Kd5 Qd2+ 9. Ke6 Qe3+
>                                    10. Kf6 Qd4+ <HT>
>               12->   5.50   5.82   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kg4 Qd4+ 5. Kf3 Qc3+ 6. Kf4 Qd2+
>                                    7. Ke5 Qc3+ 8. Kd5 Qd2+ 9. Ke6 Qe3+
>                                    10. Kf6 Qd4+ <HT>
>               13     7.79     ++   1. ... Qe5+!!
>               13    13.49   4.22   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kh4 Qe7+ 5. Kh5 Qc5+ 6. Kh6 Qf8+
>                                    7. Kg5 Qe7+ 8. Kf4 Qd6+ 9. Ke3 Qg3+
>                                    10. Kd2 Qxg2+ 11. Ke3 Qg3+ 12. Kd4
>                                    Qd6+ 13. Kc4 Qc7+ 14. Kb4 Qd8
>               13->  14.55   4.22   1. ... Qe5+ 2. Kh3 Qh5+ 3. Kg3 Qe5+
>                                    4. Kh4 Qe7+ 5. Kh5 Qc5+ 6. Kh6 Qf8+
>                                    7. Kg5 Qe7+ 8. Kf4 Qd6+ 9. Ke3 Qg3+
>                                    10. Kd2 Qxg2+ 11. Ke3 Qg3+ 12. Kd4
>                                    Qd6+ 13. Kc4 Qc7+ 14. Kb4 Qd8
>               14    25.82     ++   1. ... Qe5+!!
>               14    27.55   2.00   1. ... Qe5+ 2. Kh3 Qe6+ 3. g4 Qe3+
>                                    4. Kh2 Qf4+ 5. Kg2 Qxg4+ 6. Kf2 Qf4+
>                                    7. Ke2 Qg4+ 8. Ke3 Qg3+ 9. Kd4 Qd6+
>                                    10. Ke4 Qb4+ 11. Kd5 Qxb1 12. h8=Q
>                                    Qa2+ 13. Kc6 Qc2+ 14. Kd6
>               14->  29.02   2.00   1. ... Qe5+ 2. Kh3 Qe6+ 3. g4 Qe3+
>                                    4. Kh2 Qf4+ 5. Kg2 Qxg4+ 6. Kf2 Qf4+
>                                    7. Ke2 Qg4+ 8. Ke3 Qg3+ 9. Kd4 Qd6+
>                                    10. Ke4 Qb4+ 11. Kd5 Qxb1 12. h8=Q
>                                    Qa2+ 13. Kc6 Qc2+ 14. Kd6
>               15    32.80   2.00   1. ... Qe5+ 2. Kh3 Qe6+ 3. g4 Qe3+
>                                    4. Kh2 Qf4+ 5. Kg2 Qxg4+ 6. Kf2 Qf4+
>                                    7. Ke2 Qg4+ 8. Ke3 Qg3+ 9. Kd4 Qd6+
>                                    10. Ke4 Qb4+ 11. Kd5 Qxb1 12. h8=Q
>                                    Qa2+ 13. Kd6 Qd2+ 14. Kc7 Qc2+ <HT>
>               15->  34.79   2.00   1. ... Qe5+ 2. Kh3 Qe6+ 3. g4 Qe3+
>                                    4. Kh2 Qf4+ 5. Kg2 Qxg4+ 6. Kf2 Qf4+
>                                    7. Ke2 Qg4+ 8. Ke3 Qg3+ 9. Kd4 Qd6+
>                                    10. Ke4 Qb4+ 11. Kd5 Qxb1 12. h8=Q
>                                    Qa2+ 13. Kd6 Qd2+ 14. Kc7 Qc2+ <HT>
>               16    46.88     --   1. ... Qe5+
>              time=60:01  cpu=201%  mat=2  n=1693306751  fh=99%  nps=470k
>              ext-> chk=1363197943 cap=274706 pp=267447 1rep=117221890 mate=2380
>
>              predicted=0  nodes=1693306751  evals=7323296
>              endgame tablebase-> probes done=48149  successful=4738
>              hashing-> trans/ref=73%  pawn=99%  used=14%
>              SMP->  split=4869  stop=472  data=13/32  cpu=120:40  elap=60:01
>Black(1):
>
>
>Fails low @ 46 seconds, and can't resolve it in 59 minutes.  :(

This looks like a bug.  That position should never fail low, but always fail
high.

Either that, or crafty may have found some strange, suicidal attack that
succeeds.




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