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Subject: Re: Hard position?

Author: Uri Blass

Date: 01:04:30 01/03/01

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On January 03, 2001 at 03:35:57, Pete Galati wrote:

>On January 02, 2001 at 02:45:27, Ferdinand S. Mosca wrote:
>
>>On January 02, 2001 at 01:24:15, Steve Timson wrote:
>>
>>>This position is from a game Chester played on ICC vs. a human.
>>>
>>>[D] 1r3rk1/pbqnnppp/4p3/2ppP3/p2P4/B1PB1N2/2P2PPP/R2QR1K1 w - - 0 15
>>>
>>>Chester's opponent played Bxh7 and went on to win.  Chester has a very hard time
>>>understanding this position.  It doesn't realize Bxh7 is a good move until a few
>>>moves down the resulting sequence (Bxh7 Kxh7 Ng5+ Kg6 and it sees the swing
>>>after Qg4).  How do other programs do here?  Do they see Bxh7 in a reasonable
>>>time period?
>>>
>>> - Steve
>>
>>
>>
>>Hi Steve,
>>
>>Yace on P3_450 found Bxh7 in less than 27 seconds.
>>This position is a bit hard for programs since it gives up material.
>>
>>Dinan
>
>With the Dos Comet on a Celeron700 in Windows, approx 18mb hash, it took 77
>seconds.  I have doubts that this is very difficult for a program at all.  They
>can see the King getting trapped real fast.  I just wish I could see the rest of
>what Comet is thinking, but that King appears to be in big trouble.
>
>Pete
>
>Comet-B.27    Wed Jan  3 02:12:29 2001
>
>depth	score	  sec	  nodes		  pv
> 1.	+0.19	    0	      947	 d3b5
> 2.	+0.15	    0	     3466	 a3c5  d7c5  d4c5  c7c5  a1a4
> 3.	+0.15	    0	    10709	 a3c5  d7c5  d4c5  c7c5  a1a4
> 4.	+0.11	    0	    12140	 a3c5  d7c5  d4c5  f8c8  f3g5
> 4.	+0.11	    0	    41242	 a3c5  d7c5  d4c5  f8c8  f3g5
> 5.	+0.02	    0	    49891	 a3c5  d7c5  d4c5  f8c8  a1a4  c7c5  d1d2
> 5.	+0.11	    0	    80031	 d1d2  f8e8  d4c5  e8c8  a3b4  d7c5  b4c5
> 5.	+0.11	    1	   133031	 d1d2  f8e8  d4c5  e8c8  a3b4  d7c5  b4c5
> 6.	+0.14	    2	   245899	 d1d2  f8e8  a3c5  d7c5  d4c5  c7a5  e1b1
> 6.	+0.14	    5	   766414	 d1d2  f8e8  a3c5  d7c5  d4c5  c7a5  e1b1
> 7.	+0.13	    7	  1067950	 d1d2  f8c8  e1b1  e7g6  a3c5  d7c5  d3g6
> 7.	+0.13	   12	  1694460	 d1d2  f8c8  e1b1  e7g6  a3c5  d7c5  d3g6
> 8.	+0.04	   24	  3132774	 d1d2  f8e8  e1b1  b7a8  d2g5  b8b1  a1b1
> 8!	+0.26	   77	 11278271	 d3h7  g8h7  f3g5  h7h6  d1g4  e7g6  g5e6
> 8!	+0.53	   79	 11826970	 d3h7  g8h7  f3g5  h7h6  d1g4  c5d4  a3e7
> 8.	+0.56	   83	 12775906	 d3h7  g8h7  f3g5  h7g6  d1g4  f7f5  a3b4
> 8.	+0.56	   83	 12798067	 d3h7  g8h7  f3g5  h7g6  d1g4  f7f5  a3b4
> 9?	+0.42	   85	 13314268	 d3h7  g8h7  f3g5  h7g6  d1g4  f7f5  g4f5
> 9?	+0.15	  113	 18995944	 d3h7  g8h7  d4c5
> 9.	+0.15	  114	 19120060	 d3h7  g8h7  d4c5
>
>==> My Move: d3h7 in 1:59

CometB27(64 mbytes hash under chessbase) had a fail low without solving it.
It is a bad point to stop it.
If you give Comet more time it is going to solve the fail low and see a negative
score for Bxh7+ and it is going to change its mind to Qd2

Comet can find Bh7 again at depth 10 and it fail high again and again to get
+1.61 score after 4:47 on pIII800.

It fails high again at depth 11 and it can see +1.97 score after 6:15 and +1.99
at depth 12 after 9:11.
It fails high again at depth 13 with score of +2.12 after 13:38

I agree that the position is not very hard but your result for Comet is too
optimistic because you stopped it before it had an opportunity to see the
tactical reason.

The times are not exactly correct and may be slightly smaller because the p800
did another task(this post)

Uri



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