Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Fine #70 and hash bug(s) (warning: long post)

Author: Andrew Williams

Date: 12:49:14 04/19/04

Go up one level in this thread


On April 18, 2004 at 19:56:25, Andrew Wagner wrote:

Try searching longer. PM is getting this at ply 27 (78kns, 0.76 seconds) at the
moment, although I've seen it return the correct move at various different plies
over the years.

Andrew

>     Ok, I've been banging my head against this one all day. This is Fine #70:
>[d]8/k7/3p4/p2P1p2/P2P1P2/8/8/K7 w - -
>
>     Below is Trueno's output for the position. Of course, the correct result is
>+1.8 (Trueno counts pawns as .9) with the best move of Kb1. It finds that but
>then changes its mind. I've been told that this position is generally infamous
>for catching hash bugs. Anyone have any suggestions how to attack this one? Null
>move is off, and I'm evaluating material only, using a single replace-always
>hash table. Any suggestions would be VERY much appreciated). Andrew
>
>           -------------------------------
>        8 | . | . | . | . | . | . | . | . |
>          |-------------------------------|
>        7 | k | . | . | . | . | . | . | . |
>          |-------------------------------|
>        6 | . | . | . | p | . | . | . | . |
>          |-------------------------------|
>        5 | p | . | . | P | . | p | . | . |
>          |-------------------------------|
>        4 | P | . | . | P | . | P | . | . |
>          |-------------------------------|
>        3 | . | . | . | . | . | . | . | . |
>          |-------------------------------|
>        2 | . | . | . | . | . | . | . | . |
>          |-------------------------------|
>        1 | K | . | . | . | . | . | . | . |
>           -------------------------------
>            A   B   C   D   E   F   G   H
>
>Fifty: 0  En Passant: 0
>Castle: 0000
>Ply: 0  To move: True
>
>
>1. Score: .9; Time: 0; nodes: 4; PV: a1-b2
>2. Score: .9; Time: 0; nodes: 15; PV: a1-b2 a7-b6
>3. Score: .9; Time: 0; nodes: 48; PV: a1-b2 a7-b6 b2-c3
>4. Score: .9; Time: 0; nodes: 111; PV: a1-b2 a7-b6 b2-c3 b6-c7
>5. Score: .9; Time: 0; nodes: 231; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4
>6. Score: .9; Time: 0; nodes: 408; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>7. Score: .9; Time: 0; nodes: 671; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7 c4-d3
>8. Score: .9; Time: 0; nodes: 1003; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7
>9. Score: .9; Time: 0; nodes: 1443; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4
>10. Score: .9; Time: 0; nodes: 1968; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4 e7-d7
>11. Score: .9; Time: 0; nodes: 2735; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4 e7-d7 c4-d3
>12. Score: .9; Time: 0; nodes: 3522; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7
>13. Score: .9; Time: 0; nodes: 4416; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4
>14. Score: .9; Time: 1; nodes: 5410; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4 e7-d7
>15. Score: .9; Time: 1; nodes: 6584; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4 e7-d7 c4-d3
>16. Score: .9; Time: 1; nodes: 7885; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7
>17. Score: .9; Time: 1; nodes: 9273; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4
>18. Score: .9; Time: 1; nodes: 10845; PV: a1-b2 a7-b6 b2-c3 b6-c7 c3-c4 c7-d7
>c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4 e7-d7
>19. Score: .9; Time: 1; nodes: 16249; PV: a1-b2 a7-b6 b2-c3 b6-b7 c3-c4 b7-b6
>c4-d3 b6-c7 d3-c4 c7-d7 c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4 e7-d7 c4-d3
>20. Score: .9; Time: 1; nodes: 18816; PV: a1-b2 a7-b6 b2-c3 b6-b7 c3-c4 b7-b6
>c4-d3 b6-c7 d3-c4 c7-d7 c4-d3 d7-e7 d3-c4 e7-d7 c4-d3 d7-e7 d3-c4 e7-d7 c4-d3
>d7-e7
>21. Score: 1.8; Time: 2; nodes: 30305; PV: a1-b1 a7-b6 b1-c2 b6-b7 c2-d2 b7-c7
>d2-d3 c7-b6 d3-e3 b6-c7 e3-f3 c7-d7 f3-g3 d7-e7 g3-h4 e7-f6 h4-h5 f6-f7 h5-g5
>f7-e8 g5-f5
>22. Score: 1.8; Time: 2; nodes: 40127; PV: a1-b1 a7-b6 b1-c2 b6-b7 c2-d2 b7-c7
>d2-d3 c7-b6 d3-e3 b6-c7 e3-f3 c7-d7 f3-g3 d7-e7 g3-h4 e7-f6 h4-h5 f6-f7 h5-g5
>f7-e8 g5-f5 e8-e7
>23. Score: 1.8; Time: 2; nodes: 50869; PV: a1-b1 a7-b6 b1-c2 b6-b7 c2-d2 b7-c7
>d2-d3 c7-b6 d3-e3 b6-c7 e3-f3 c7-d7 f3-g3 d7-e7 g3-h4 e7-f6 h4-h5 f6-f7 h5-g5
>f7-e8 g5-f5 e8-e7 f5-e4
>24. Score: 1.8; Time: 3; nodes: 64039; PV: a1-a2 a7-b6 a2-b3 b6-c7 b3-c3 c7-b6
>c3-c2 b6-a6 c2-d2 a6-b6 d2-e3 b6-c7 e3-f3 c7-d7 f3-g3 d7-e7 g3-h4 e7-f6 h4-h5
>f6-f7 h5-g5 f7-e8 g5-f5 e8-e7
>25. Score: 1.8; Time: 3; nodes: 75500; PV: a1-b2 a7-b6 b2-c3 b6-b7 c3-d2 b7-c7
>d2-d3 c7-b6 d3-e3 b6-c7 e3-f3 c7-d7 f3-g3 d7-e7 g3-h4 e7-f6 h4-h5 f6-f7 h5-g5
>f7-e8 g5-f5 e8-e7 f5-e4 e7-d7 e4-f5
>26. Score: 1.8; Time: 4; nodes: 83644; PV: a1-b2 a7-b6 b2-c3 b6-b7 c3-d2 b7-c7
>d2-d3 c7-b6 d3-e3 b6-c7 e3-f3 c7-d7 f3-g3 d7-e7 g3-h4 e7-f6 h4-h5 f6-f7 h5-g5
>f7-e8 g5-f5 e8-e7 f5-e4 e7-d7 e4-f5 d7-e7
>I play a1-b2
>Nodes: 83k; NPS: 21414; QNodes: 0; MO%: 98; FHA: 2; HC%: 55; Hash%: 58; NM%: 0;
>egtb hits: 0; Ext's: 0; Total time searched: 3.906
>
>(MO% = first-move fail-high percent; FHA isn't important; HC is the percent of
>time the hash move causes a cutoff; Hash% is the percent of time I find the move
>in the hash table; the rest is un-important)
>
>(told you it was a long post)



This page took 0.01 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.