Author: Jeremiah Penery
Date: 13:14:51 10/04/02
Go up one level in this thread
On October 04, 2002 at 06:30:02, Omid David wrote:
>On October 03, 2002 at 22:47:58, Jeremiah Penery wrote:
>
>>On October 03, 2002 at 22:07:38, Omid David wrote:
>>
>>>On October 03, 2002 at 21:30:56, Jeremiah Penery wrote:
>>>
>>>>On October 03, 2002 at 20:39:02, Omid David wrote:
>>>>
>>>>>Quite impressive, just 1.02% slower (paractically negligible). Do you invoke
>>>>>that detection at every node in the search tree?
>>>>
>>>>Yes, but most of the time it exits very quickly (a couple of 'if' clauses). I
>>>>could probably make it cost even less, but I'm not very interested in doing that
>>>>yet.
>>>
>>>But the problem may arise in the endgames where there are a number of pawns and
>>>pieces left which can potentially cause a "block draw". Then in the draw
>>>detection heuristic, almost in every node you'll pass the first few 'if's and
>>>will have to step into a detailed assessment of the position. How much does it
>>>slow down there, in comparison to the non-detecting version?
>>
>>I'm not really sure, and I suspect it depends highly on the kind of position.
>>If you have any specific ones, I'll be happy to test them.
>>
>
>Let's compare the following two very similar positions:
>
>The first one - White wins:
>[D] 8/8/8/k3p3/1p1pPp2/1PpP1P2/K1P3B1/8 w - - 0 1
With detection:
1 0.00 3.37 1. Bf1
1-> 0.00 3.37 1. Bf1
........................................................
40 9.42 16.69 1. Bh3 Kb6 2. Kb1 Kc5 3. Kc1 Kd6 4.
Kd1 Kc5 5. Ke2 Kd6 6. Kf1 Ke7 7. Kg2
Kf6 8. Bd7 Kg5 9. Kh3 Kh5 10. Be6 Kg5
11. Bg4 Kg6 12. Kh4 Kf6 13. Kh5 Ke7
14. Kg6 Kd6 15. Kf5 Kc6 16. Kxe5 Kc5
17. Bf5 Kc6 18. Kxd4 Kb6 19. Be6 <HT>
40-> 9.44 16.69 1. Bh3 Kb6 2. Kb1 Kc5 3. Kc1 Kd6 4.
Kd1 Kc5 5. Ke2 Kd6 6. Kf1 Ke7 7. Kg2
Kf6 8. Bd7 Kg5 9. Kh3 Kh5 10. Be6 Kg5
11. Bg4 Kg6 12. Kh4 Kf6 13. Kh5 Ke7
14. Kg6 Kd6 15. Kf5 Kc6 16. Kxe5 Kc5
17. Bf5 Kc6 18. Kxd4 Kb6 19. Be6 <HT>
Elapsed Time: 9.53, CPU Time: 9.14, CPU Use: 95%
Material Balance: 350, Previous Moves Predicted: 0
Nodes: 11095548, Evaluations: 429230, FH%: 96%, NPS: 1164k
EXTENSIONS->
Threat: 170, Passed Pawn: 63583, Recapture: 24
One-Reply: 11838, Check: 329803
PRUNING-> Razors-> White: 48556, Black: 0
Futility-> White: 3588305, Black: 0
TABLEBASES-> Probes: 4, Successful: 2
HASH TABLES-> Hash Hits: 119% (6367576/5340586)
Pawn Hash Hits: 99% (4546488/4549102)
Hash Table Filled: 42%
Without:
1 0.00 3.37 1. Bf1
1-> 0.00 3.37 1. Bf1
.........................................................
40 8.92 16.69 1. Bh3 Kb6 2. Kb1 Kc5 3. Kc1 Kd6 4.
Kd1 Kc5 5. Ke2 Kd6 6. Kf1 Ke7 7. Kg2
Kf6 8. Bd7 Kg5 9. Kh3 Kh5 10. Be6 Kg5
11. Bg4 Kg6 12. Kh4 Kf6 13. Kh5 Ke7
14. Kg6 Kd6 15. Kf5 Kc6 16. Kxe5 Kc5
17. Bf5 Kc6 18. Kxd4 Kb6 19. Be6 <HT>
40-> 8.93 16.69 1. Bh3 Kb6 2. Kb1 Kc5 3. Kc1 Kd6 4.
Kd1 Kc5 5. Ke2 Kd6 6. Kf1 Ke7 7. Kg2
Kf6 8. Bd7 Kg5 9. Kh3 Kh5 10. Be6 Kg5
11. Bg4 Kg6 12. Kh4 Kf6 13. Kh5 Ke7
14. Kg6 Kd6 15. Kf5 Kc6 16. Kxe5 Kc5
17. Bf5 Kc6 18. Kxd4 Kb6 19. Be6 <HT>
Elapsed Time: 9.02, CPU Time: 8.75, CPU Use: 97%
Material Balance: 350, Previous Moves Predicted: 0
Nodes: 11095548, Evaluations: 429230, FH%: 96%, NPS: 1230k
EXTENSIONS->
Threat: 170, Passed Pawn: 63583, Recapture: 24
One-Reply: 11838, Check: 329803
PRUNING-> Razors-> White: 48556, Black: 0
Futility-> White: 3588305, Black: 0
TABLEBASES-> Probes: 4, Successful: 2
HASH TABLES-> Hash Hits: 119% (6367576/5340586)
Pawn Hash Hits: 99% (4546488/4549102)
Hash Table Filled: 42%
>The second one - Draw:
>[D] 8/8/8/k3p1p1/1p1pPpP1/1PpP1P2/K1P3B1/8 w - - 0 1
With detection:
1 0.00 0.00 1. Bh3
1-> 0.00 0.00 1. Bh3
..........................................
60 0.10 0.00 1. Bh3 Kb5 2. Bg2 Ka5
60-> 0.10 0.00 1. Bh3 Kb5 2. Bg2 Ka5
Elapsed Time: 0.18, CPU Time: 0.06, CPU Use: 33%
Material Balance: 350, Previous Moves Predicted: 0
Nodes: 72459, Evaluations: 1, FH%: 100%, NPS: 402k
EXTENSIONS->
Threat: 0, Passed Pawn: 0, Recapture: 0
One-Reply: 0, Check: 0
PRUNING-> Razors-> White: 0, Black: 0
Futility-> White: 0, Black: 0
TABLEBASES-> Probes: 0, Successful: 0
HASH TABLES-> Hash Hits: 100% (51906/51810)
Pawn Hash Hits: 0% (0/1)
Hash Table Filled: 0%
Without:
1 0.00 3.31 1. Bf1
1-> 0.00 3.31 1. Bf1
........................................................
60 0.42 3.15 1. Kb1 Kb6 2. Kc1 Kb5 3. Kd1 Kb6 4.
Ke2 Kc5 5. Kf2 Kc6 6. Kg1 Kc5 7. Bh3
Kb5 8. Kf2 Kc6 9. Kf1 Kc5 10. Kg2 Kc6
11. Kf2 Kd6 12. Ke2 Kc5 13. Kf1 Kb6
14. Ke1 Kc6 15. Bg2 Kd6 16. Bf1 Kc7
17. Ke2 Kb7 18. Bg2 Kb6 19. Bh1 Kc6
20. Kf1 Kb5 21. Bg2 Kb6 22. Ke1 Kb5
23. Bf1 Kb6 24. Kf2 Kc6 25. Be2 Kc5
26. Bd1 Kd6 27. Ke2 Kc5 28. Kf1 Kd6
29. Ke1 Kc5 30. Ke2 Kd6
60-> 0.42 3.15 1. Kb1 Kb6 2. Kc1 Kb5 3. Kd1 Kb6 4.
Ke2 Kc5 5. Kf2 Kc6 6. Kg1 Kc5 7. Bh3
Kb5 8. Kf2 Kc6 9. Kf1 Kc5 10. Kg2 Kc6
11. Kf2 Kd6 12. Ke2 Kc5 13. Kf1 Kb6
14. Ke1 Kc6 15. Bg2 Kd6 16. Bf1 Kc7
17. Ke2 Kb7 18. Bg2 Kb6 19. Bh1 Kc6
20. Kf1 Kb5 21. Bg2 Kb6 22. Ke1 Kb5
23. Bf1 Kb6 24. Kf2 Kc6 25. Be2 Kc5
26. Bd1 Kd6 27. Ke2 Kc5 28. Kf1 Kd6
29. Ke1 Kc5 30. Ke2 Kd6
Elapsed Time: 0.50, CPU Time: 0.35, CPU Use: 70%
Material Balance: 350, Previous Moves Predicted: 0
Nodes: 423567, Evaluations: 11897, FH%: 89%, NPS: 847k
EXTENSIONS->
Threat: 0, Passed Pawn: 0, Recapture: 0
One-Reply: 0, Check: 0
PRUNING-> Razors-> White: 0, Black: 0
Futility-> White: 0, Black: 0
TABLEBASES-> Probes: 0, Successful: 0
HASH TABLES-> Hash Hits: 142% (507475/355091)
Pawn Hash Hits: 99% (11897/11898)
Hash Table Filled: 1%
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