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Subject: Re: Chess program improvement project (copy at Winboard::Programming)

Author: Tony Werten

Date: 23:27:24 03/06/06

Go up one level in this thread


On March 07, 2006 at 00:35:43, Stuart Cracraft wrote:

>On March 07, 2006 at 00:25:46, Stuart Cracraft wrote:
>
>>On March 06, 2006 at 22:50:44, Dann Corbit wrote:
>>
>>>Looks like king safety to me:
>>>[D] r4rk1/1p2ppbp/p2pbnp1/q7/3BPPP1/2N2B2/PPP4P/R2Q1RK1 b - - bm Bxg4
>>
>>An extended search could not crack the 10th ply aspiration search fail high
>>on this position. I do not know what was about to happen, only that it
>>would take a long time.
>>
>>.sd 99
>>maxdepth = 99 maxtime = 9999999 timed = 0
>>.ts
>>position file? [wac.epd] retry.epd
>># of test positions to test? 1
>>maxtime = 9999999
>>Interrupt current ply and return move at timeout
>>Testsuite: Tests/retry.epd 1 positions
>>*** Problem   Solution(s): Bxg4 (bm)
>>[D] r4rk1/1p2ppbp/p2pbnp1/q7/3BPPP1/2N2B2/PPP4P/R2Q1RK1 b - - bm Bxg4
>>*** Problem   Solution(s): Bxg4 (bm)
>>BR ** -- ** -- BR BK **
>>** BP ** -- BP BP BB BP
>>BP ** -- BP BB BN BP **
>>BQ -- ** -- ** -- ** --
>>-- ** -- WB WP WP WP **
>>** -- WN -- ** WB ** --
>>WP WP WP ** -- ** -- WP
>>WR -- ** WQ ** WR WK --
>>mv 1 stage 0, black to move, computer plays black
>>hash=5076cc275e393397
>>pawnhash=3d032756da421438
>>0 0 0 0 0 0
>>Alpha=999 Beta=1800 Maxdepth=99 MaxTime=9999999 xboard=0
>>Itr/Max Mv   Score   Time Nodes PV
>> 1/ 5  f6g4 1400  0.00       57 f6g4
>> 2/10  f6g4 1347  0.01      385 f6g4 f3e2 g7d4 d1d4
>> 3/10< f6g4 946  0.03     1959 f6g4 f3e2 g7d4 d1d4 f7f6
>> 3/10  f6g4 945  0.05     2925 f6g4 d4g7 g8g7 f3g4
>> 4/12< f6g4 544  0.10     6880 f6g4 d4g7 g8g7 f3g4 f7f6
>> 4/15  a5d8 -241  0.25    17921 a5d8 g1g2
>> 5/21  e6c4 -35  0.46    33988 e6c4 f3e2 a5c7
>> 6/21  h7h5 -40  1.30   101881 h7h5 g4g5 f6d7 d4g7 g8g7
>> 7/21  a5b4 -104  2.96   235870 a5b4 g4g5 f6h5 d4g7 h5g7 a1b1 a8c8
>> 8/22  a5b4 -145  6.09   498480 a5b4 a2a3 b4b2 c3d5 b2b5 d5e7 g8h8 a1b1
>> 9/24  e6c4 -79 11.79   991796 e6c4 f1f2 e7e5 d4e3 a5d8 a2a4
>>10/24> e6c4 321 30.18  2576527 e6c4 f1f2 e7e5 d4e3 a5b4 g4g5 f6d7 f4e5 g7e5
>>10/
>
>The search kept going and did find the move but it took almost 15 minutes.
>
>position file? [wac.epd] retry.epd
># of test positions to test? 1
>maxtime = 9999999
>Interrupt current ply and return move at timeout
>Testsuite: Tests/retry.epd 1 positions
>*** Problem   Solution(s): Bxg4 (bm)
>[D] r4rk1/1p2ppbp/p2pbnp1/q7/3BPPP1/2N2B2/PPP4P/R2Q1RK1 b - - bm Bxg4
>*** Problem   Solution(s): Bxg4 (bm)
>BR ** -- ** -- BR BK **
>** BP ** -- BP BP BB BP
>BP ** -- BP BB BN BP **
>BQ -- ** -- ** -- ** --
>-- ** -- WB WP WP WP **
>** -- WN -- ** WB ** --
>WP WP WP ** -- ** -- WP
>WR -- ** WQ ** WR WK --
>mv 1 stage 0, black to move, computer plays black
>hash=5076cc275e393397
>pawnhash=3d032756da421438
>0 0 0 0 0 0
>Alpha=999 Beta=1800 Maxdepth=99 MaxTime=9999999 xboard=0
>Itr/Max Mv   Score   Time Nodes PV
> 1/ 5  f6g4 1400  0.00       57 f6g4
> 2/10  f6g4 1347  0.01      385 f6g4 f3e2 g7d4 d1d4
> 3/10< f6g4 946  0.03     1959 f6g4 f3e2 g7d4 d1d4 f7f6
> 3/10  f6g4 945  0.05     2925 f6g4 d4g7 g8g7 f3g4
> 4/12< f6g4 544  0.10     6880 f6g4 d4g7 g8g7 f3g4 f7f6
> 4/15  a5d8 -241  0.25    17921 a5d8 g1g2
> 5/21  e6c4 -35  0.46    33988 e6c4 f3e2 a5c7
> 6/21  h7h5 -40  1.30   101881 h7h5 g4g5 f6d7 d4g7 g8g7
> 7/21  a5b4 -104  2.96   235870 a5b4 g4g5 f6h5 d4g7 h5g7 a1b1 a8c8
> 8/22  a5b4 -145  6.09   498480 a5b4 a2a3 b4b2 c3d5 b2b5 d5e7 g8h8 a1b1
> 9/24  e6c4 -79 11.79   991796 e6c4 f1f2 e7e5 d4e3 a5d8 a2a4
>10/24> e6c4 321 30.18  2576527 e6c4 f1f2 e7e5 d4e3 a5b4 g4g5 f6d7 f4e5 g7e5
>10/25  e6g4 1344 863.20  4198040 e6g4 e4e5 d6e5 f4e5 g4f3 d1f3 a5b4 f3e3 f6g4
>11/26  e6g4 1032 889.10  6506793 e6g4 e4e5 d6e5 f4e5 g4f3 d1f3 a5b4 a1d1 f6h5
>b2b3
>12/30  e6g4 1261 957.00 12603674 e6g4 f3g4 f6g4 c3d5 g7d4 d1d4 a8e8 h2h3 g4h6
>b2b4 a5a3
>13/32  e6g4 1285 1110.45 26675821 e6g4 f3g4 f6g4 c3d5 g7d4 d1d4 a8e8 h2h3 g4f6
>d5f6 e7f6 d4d6 e8e4 b
>2b4 f8d8
>14/

My guess is something is wrong with your move ordering. The failhigh on ply 10
took 30 times the previous. That should not happen.

What I further noticed (might be related) is that your mainline hardly ever has
at least the length of your iteration depth.

My first try would be dropping the pruning.

Cheers,

Tony



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