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Subject: Re: Engine woes

Author: Nathan Thom

Date: 15:23:31 04/16/03

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On April 16, 2003 at 07:48:04, Vincent Diepeveen wrote:

>On April 15, 2003 at 19:00:07, Nathan Thom wrote:
>
>>On April 15, 2003 at 10:23:01, Vincent Diepeveen wrote:
>>
>>>On April 15, 2003 at 08:03:36, Nathan Thom wrote:
>>>
>>>>My engine is giving me headaches :) Its performing pretty badly against test
>>>>positions (even thought it can beat me!). I have concerns over the following
>>>>statistics:
>>>>
>>>>1. The PVS search success ratio seems extremely high, of 180k attempts, only 9
>>>>fail (ie value > alpha && value < beta).
>>>>
>>>>2. When writing to the hash table, of 50k writes 40k are lower bounds, 10k upper
>>>>bounds, 20 exact.
>>>>
>>>>Does anyone else have any statistics for what I should be getting, or any
>>>>suggestions where to look for errors???
>>>
>>>what position and depth did you test?
>>
>>For these particular numbers i used
>>
>>[D]4r1r1/bB4p1/8/2p1kPKn/n7/3R4/3P4/2B5 w
>>
>>and searched to a depth of around 6 or 7 i think.
>
>Took 0.13 seconds to start all 1 other processes out of 2
>00:00   1469   1k 0 0 1469 (2) 2 (0,0) 0.000 Rd3-d5 Ke5-e4 Rd5-d7 Ke4-e5 Rd7-d5
>
>00:00 154880 155k 0 0 7744 (2) 3 (0,6) 0.000 Rd3-d5 Ke5-e4 Rd5-d7 Ke4-e5 Rd7-d5
>
>00:00 207070 207k 0 0 20707 (2) 4 (0,15) 0.000 Rd3-d5 Ke5-e4 Rd5-d7 Ke4-e5 Rd7-d
>5
>00:00 244484 244k 0 0 46452 (2) 5 (0,32) 0.000 Rd3-d5 Ke5-e4 Rd5-d7 Ke4-e5 Rd7-d
>5
>00:00 235494 235k 0 0 89488 (2) 6 (1,64) 0.000 Rd3-d5 Ke5-e4 Rd5-d7 Ke4-e5 Rd7-d
>5
>00:02 164338 164k 0 0 433853 (2) 7 (14,143) 5.941 Rd3-d5 Ke5-e4 Rd5-d7 Ke4-e5 Bc
>1-a3 c5-c4 Ba3-d6 Ke5-d4 Bd6-f8 Kd4-e5 Rd7-d5 Ke5-e4 Rd5-d8 Ke4-e5 Rd8xe8 Ke5-d4
> Re8-d8 Kd4-e5 Rd8-d5 Ke5-e4 Rd5-d7 Ke4-e5 Bf8-d6 Ke5-d4 Bd6-b8 Kd4-c5 Bb8xa7 Kc
>5-b4 Kg5xh5
>00:03 202307 202k 0 0 793047 (2) 8 (31,333) MATE16 Rd3-d5 Ke5-e4 Rd5-d7 Ke4-e5 B
>c1-a3 c5-c4 Ba3-d6 Ke5-d4 Bd6-f8 Kd4-e5 Rd7-d5 Ke5-e4 Rd5-d8 Ke4-e5 Rd8xe8 Ke5-d
>4 Re8-d8 Kd4-e5 Rd8-d5 Ke5-e4 Rd5-d7 Ke4-e5 Bf8-d6 Ke5-d4 Bd6-b4 Kd4-e5 d2-d4 c4
>xd3 Rd7-e7 Ke5-d4 Re7-e4
>
>Hmm not sure such positions are good ones to test with. In general mate in x
>positions are very bad to generate statistics as they are unreliable and
>depending upon different move ordering and different branching factors and more
>upon extensions and quiescencesearch.
>
>So testing anything at it except whether your extensions work well should be
>avoided.

thanks. im not using any extensions yet, which i thought might be one reason for
its poor performance.



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