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Subject: Re: Slow EGTBs - test position

Author: Eugene Nalimov

Date: 14:03:07 01/16/03

Go up one level in this thread


Simplest probable explanation is: you are probing everywhere when you have the
opportunity. Crafty (and I presume some other programs) probe only first M
plies. E.g. when they are doing N-ply search from the root position they probe
only first N*2 plies (or N*3/2, or ... -- you got the idea).

Thanks,
Eugene

On January 16, 2003 at 16:33:52, David Rasmussen wrote:

>On January 16, 2003 at 15:54:17, Dann Corbit wrote:
>
>>>
>>>Beowulf output:
>>>Position 1 - White to play
>>>--------------------------
>>>ID =
>>>FEN = 8/4n3/1k6/1p4p1/1P4P1/1K6/3B4/8 w - -
>>>
>>>. . . . . . . .
>>>. . . . n . . .
>>>. k . . . . . .
>>>. p . . . . p .
>>>. P . . . . P .
>>>. K . . . . . .
>>>. . . B . . . .
>>>. . . . . . . .
>>>
>>>Current Position = 0.52
>>>Number of Possible Moves = 11
>>>
>>> 11    236      75     143184   Bxg5 Ng6 Kc3 Ne5 Be3+ Kc6 g5 Kd7 Kd4 Ke6 g6
>>> 12    231     178     352812   Bxg5 Ng6 Kc3 Ne5 Be3+ Kc6 g5 Kd5 Bd4 Nf3 g6 Kd6
>>> 13    219     266     528614   Bxg5 Ng6 Kc3 Ne5 Bd8+ Kc6 g5 Kd7 Bf6 Ng4 Kd3 Ke6
>>>Bd8 Kf5
>>> 14    213     606    1216211   Bxg5 Nd5 Bd2 Kc6 g5 Ne7 Kc3 Kd5 Kd3 Ke5 Be1
>>> 15    213    1009    1942140   Bxg5 Nd5 Bd2 Kc6 g5 Ne7 Bc3 Kd5 Bf6 Ng6 Kc2 Ke4
>>>Bd8 Ke5 Bf6+ Ke4 &rep.
>>> 16    214    1759    3325204   Bxg5 Nd5 Bc1 Kc6 Kc2 Nxb4+ Kb3 Nd3 Bd2 Kd5 Kc3
>>>Ne5 Kb3
>>> 17    214    3000    5733741   Bxg5 Nd5 Bc1 Kc6 g5 Ne7 Kc2 Kd5 Kd3 Ke5 Bd2 Nd5
>>>Be1 Ne7
>>>
>>>Search Time : 30.00 Seconds
>>>Total Nodes Searched   : 5733741  (52.3% Qui)
>>>Total Nodes Evaluated  : 2998609
>>>Cuts       : Delta     1508  : SEE       18270  : Mate          0
>>>           : Razor   202628  : Eval    1107291
>>>Extensions : Check   151560  : OneRep       45  : CMThreat   8317
>>>           : Pawn     42183  : Recap      2342  : RevCheck   4278
>>>Hash Stores (Size) : 582291  (699037)
>>>Hash Probes (Hits) : 5384740  (3263270)
>>>EGTB Probes (Hits) : 46423  (46423)
>>>Move Ordering      : 81.9%
>>>Best Move = Bxg5
>>>Move Score = 214
>>>--Answer: Bxg5    ** Correct **
>>>Time To Solution = 0.00 sec
>>>Correct So Far : 1/1
>>>
>>>
>>>Test Completed.
>>>Results;
>>>Correct : 1/1
>>>Average Time To Solution = 0.00 sec
>>>[1]W >
>>
>>Same thing with EGTB turned off:
>>
>>Position 1 - White to play
>>--------------------------
>>ID =
>>FEN = 8/4n3/1k6/1p4p1/1P4P1/1K6/3B4/8 w - -
>>
>>. . . . . . . .
>>. . . . n . . .
>>. k . . . . . .
>>. p . . . . p .
>>. P . . . . P .
>>. K . . . . . .
>>. . . B . . . .
>>. . . . . . . .
>>
>>Current Position = 0.52
>>Number of Possible Moves = 11
>>
>> 11    236      68     145925   Bxg5 Ng6 Kc3 Ne5 Be3+ Kc6 g5 Kd7 Kd4 Ke6 g6
>> 12    219     106     229472   Bxg5 Ng6 Kc3 Ne5 Bd8+ Kc6 g5 Kd7 Bf6 Ke6 Bd8 Ng6
>>Kd4
>> 13    218     178     396062   Bxg5 Ng6 Kc3 Ne5 Bd8+ Kc6 g5 Kd7 Bb6 Ke6 Kd4 Nc4
>>Bd8 Nd6
>> 14    211     336     771335   Bxg5 Ng6 Kc3 Ne5 Bd8+ Kc6 g5 Kd5 Bf6 Ng6 Kd3
>>Ne5+ Kc2 Ke6 Kd2 Nf7 Ke3
>> 15    211     621    1421370   Bxg5 Ng6 Kc3 Ne5 Bd8+ Kc6 g5 Kd5 Bf6 Ng6 Kd3
>>Ne5+ Kc2 Ke6 Kd2 Nf7 Ke3
>> 16    207    1947    4503141   Bxg5 Nd5 Bd2 Kc6 g5 Ne7 Kc2 Kd5 Kc3 Ke5 Kb3 Nc6
>>Be3 Kf5 Bf4
>> 17    207    3000    6998206   Bxg5 Nd5 Bd2 Kc6 g5 Kd7 Kc2 Ke6 Kd3 Kf5 Kd4 Nxb4
>>Kc5 Na2 Kxb5 Nc3+ Kc4 Ne4
>>
>>Search Time : 30.00 Seconds
>>Total Nodes Searched   : 6998206  (53.9% Qui)
>>Total Nodes Evaluated  : 3765466
>>Cuts       : Delta     1878  : SEE       24636  : Mate          0
>>           : Razor   292648  : Eval    1481897
>>Extensions : Check   181048  : OneRep       96  : CMThreat      0
>>           : Pawn     71075  : Recap      3354  : RevCheck   7484
>>Hash Stores (Size) : 742253  (699037)
>>Hash Probes (Hits) : 6474752  (3664648)
>>EGTB Probes (Hits) : 0  (0)
>>Move Ordering      : 81.9%
>>Best Move = Bxg5
>>Move Score = 207
>>--Answer: Bxg5    ** Correct **
>>Time To Solution = 0.00 sec
>>Correct So Far : 1/1
>>
>>
>>Test Completed.
>>Results;
>>Correct : 1/1
>>Average Time To Solution = 0.00 sec
>
>This seems to indicate that
>1. Beowulf probes actually more in the position. ~45000 probes vs. ~25000
>probes.
>2. Beowulf loses a little speed when using EGTBs, but not nearly enough as
>Chezzz. Beowulf goes from 700M/30s to 600M/30s. Chezzz goes from 700knps to 100
>knps. What hardware is Beowulf running on here, and how much hash, egtb cache
>etc. ?
>
>/David



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