Author: David Rasmussen
Date: 14:28:36 01/15/01
Go up one level in this thread
On January 15, 2001 at 16:15:46, Uri Blass wrote:
>On January 15, 2001 at 16:06:00, David Rasmussen wrote:
>
>>On January 15, 2001 at 10:07:42, Uri Blass wrote:
>>
>>>On January 15, 2001 at 08:33:46, David Rasmussen wrote:
>>>
>>>>On January 14, 2001 at 20:37:39, Djordje Vidanovic wrote:
>>>>
>>>>>On January 14, 2001 at 17:36:21, Dan Andersson wrote:
>>>>>
>>>>>>There is no problem. I suspect more than a few programs find Rxc6 in reasonable
>>>>>>times. The first program I tried actually found it quickly, the second too,
>>>>>>Crafty and Yace. Some others will find it later some sooner. Nothing tricky
>>>>>>about this position at all.
>>>>>>
>>>>>>Regards Dan Andersson
>>>>>
>>>>>
>>>>>Actually I believe that the position IS tough for some programs -- just look at
>>>>>the commercials listed that did not find the winning move. Of the programs that
>>>>>I tested the quickest was Patzer 3.11b which found 1.Rxc6 in a second! Also
>>>>>quick were Deep Fritz (about 20 sec), Gandalf 4.32g (20 sec), Ikarus (around 25
>>>>>sec), Fritz 5.32 (about 25 sec too), etc. Some other programs could not find
>>>>>the sequence at all. The issue here is mobility, I suspect. I had thought that
>>>>>Phalanx would be fast, but after a minute passed and it had no clue, I gave it
>>>>>up.
>>>>>
>>>>>*** Djordje
>>>>
>>>>I don't understand why this can be hard. My program Chezzz is definitely weaker
>>>>than DF, Gandalf, Fritz 5.32, and probably some or all of the others you
>>>>mention, but still, Rxc6 is the _only_ move it ever considers, even at depth=1.
>>>>It never considers any other move at all. This takes 0.02 seconds on my Cel 464.
>>>
>>>I do not understand why your program considers Rxc6 even at depth 1 because this
>>>move is losing material at depth 1.
>>>I suspect that your program is not materialistic enough and can play sacrifices
>>>that are not correct.
>>>
>>>Uri
>>
>>Chezzz is not very positional. It is fairly materialistic (unfortunately).
>>Accumulated positional scores stay well below one pawn in most positions, and in
>>this one too.
>>Judge for yourself.
>>
>>Thinking for 11 seconds.
>>time depth val variation
>>0.01 1/2 -2.32 32. Rxc6 dxc6 (0 kN)
>>0.01 1/2 -----> 36 nodes 3600 nps q 11% mo 50% h 0%
>>0.02 2/3 -2.32 32. Rxc6 dxc6 (0 kN)
>>0.03 2/3 -----> 176 nodes 5866 nps q 14% mo 93% h 0%
>>0.04 3/5 -2.32 32. Rxc6 dxc6 33. Rd3 (0 kN)
>>0.06 3/5 -----> 1271 nodes 21183 nps q 9% mo 89% h 0%
>>0.06 4/7 -2.32 32. Rxc6 dxc6 33. Rd3 Rb4 (1 kN)
>>0.10 4/7 -----> 4513 nodes 45130 nps q 13% mo 86% h 6%
>
>
>What is the score for Ra2 or R6d3 at depthes 1-4?
>
>After these moves white is only a pawn down so the score should be 1 pawn for
>black and not 2 pawns for black unless your program can see big positional
>advantage for black and not only a pawn.
>
>Uri
I'm sorry, I was wrong. There was an error in my evaluation function that made
it think that this was not an endgame position in terms of kingsafety, so the
white king was given a huge penalty for being out in the open. This lead to
several weird misevalutions. This is now cleaned up. Thanks!
Now Chezzz(C) is not so sure...
It sees the move at depth=11 after 28 seconds, and the score keeps rising until
it reaches 0.00
It stays there for quite some time. I don't know when or if it will rise
further. We'll see...
Thinking for 999 seconds.
time depth val variation
0.12 4/7 -----> 6523 nodes 54358 nps q 8% mo 92% h 14%
0.14 5/9 -0.78 32. R2d3 Rb5+ 33. Kd4 Rb4+ 34. Ke3 Re4+ 35. Kf3 Re1+
36. Kg3 (8 kN)
0.20 5/9 -0.77 32. R6d3 Rb5+ 33. Kd6 Rb4 34. Bg5 Re4 (15 kN)
0.26 5/9 -----> 21308 nodes 81953 nps q 8% mo 93% h 24%
0.31 6/9 -0.73 32. R6d3 Rb5+ 33. Kd6 Rb4 34. Bg5 Re4 35. Rc3 (28 kN)
0.40 6/10 -----> 38880 nodes 97200 nps q 9% mo 93% h 17%
0.56 7/13 -0.79 32. R6d3 Rb5+ 33. Kd6 Rb4 34. Bg5 a4 35. bxa4 Rxa4 (59 k
N)
1.11 7/13 -0.66 32. Kc4 Rb4+ 33. Kc3 Rb6 34. Rc2 Rb8 35. Rdd2 Rc8 (131 k
N)
1.41 7/13 -----> 167847 nodes 119040 nps q 11% mo 90% h 22%
2.85 8/14 -0.68 32. Kc4 a4 33. bxa4 Bxa4 34. Kd4 Rb4+ 35. Ke3 Bc6
36. Ra2 (347 kN)
3.54 8/14 -----> 436200 nodes 123220 nps q 11% mo 91% h 25%
5.14 9/15 -0.68 32. Kc4 a4 33. bxa4 Bxa4 34. Kc5 Bc6 35. Ra2 Rb5+
36. Kd4 Rb4+ 37. Ke3 (638 kN)
8.99 9/15 -0.67 32. R2d3 Rc8 33. Rd2 a4 34. bxa4 Bxa4+ 35. Kd4 (1100 kN)
9.74 9/15 -----> 1206250 nodes 123844 nps q 12% mo 91% h 34%
14.73 10/18 -0.65 32. R2d3 Rc8 33. Rc3 a4 34. bxa4 Bxa4+ 35. Kd4 Rxc3
36. Kxc3 Bc6 37. Kd4 (1782 kN)
16.66 10/18 -----> 1998411 nodes 119952 nps q 12% mo 90% h 32%
23.10 11/19 -0.65 32. R2d3 Rc8 33. Rc3 a4 34. bxa4 Bxa4+ 35. Kd4 Rxc3
36. Kxc3 Bc6 37. Kd4 Rf8 (2839 kN)
28.06 11/19 -0.54 32. Rxc6 dxc6 33. Kxc6 Kf8 34. Kc7 Ra8 35. Kb7 Re8
36. Ra2 a4 37. Rxa4 (3556 kN)
28.08 11/19 -----> 3559098 nodes 126748 nps q 12% mo 90% h 30%
29.78 12/19 -0.39 32. Rxc6 dxc6 33. Kxc6 Kf8 34. Rd5 Rc8+ 35. Kb7 Re8
36. Rxa5 Re6 37. Ra8+ Re8 38. Ra7 Re6 (3812 kN)
34.61 12/21 -----> 4518894 nodes 130566 nps q 11% mo 90% h 30%
36.55 13/20 -0.06 32. Rxc6! (4800 kN)
39.27 13/20 +0.00 32. Rxc6 dxc6 33. Kxc6 Kf8 34. Rd5 Rc8+ 35. Kb7 Re8
36. Kc7 Re6 37. Rd8+ Re8 38. Rd5 (5207 kN)
46.14 13/23 -----> 6278038 nodes 136064 nps q 10% mo 90% h 33%
49.10 14/21 +0.00 32. Rxc6 dxc6 33. Kxc6 Kf8 34. Rd5 Rc8+ 35. Kb7 Re8
36. Kc7 Re6 37. Rd8+ Re8 38. Rd5 (6723 kN)
72.40 14/25 -----> 10076180 nodes 139173 nps q 10% mo 90% h 32%
77.21 15/22 +0.00 32. Rxc6 dxc6 33. Kxc6 Kf8 34. Rd5 Rc8+ 35. Kb7 Re8
36. Kc7 Re6 37. Rd8+ Re8 38. Rd5 (10807 kN)
154.00 15/27 -----> 21295544 nodes 138282 nps q 10% mo 88% h 28%
164.34 16/24 +0.00 32. Rxc6 dxc6 33. Kxc6 Kf8 34. Rd5 Rc8+ 35. Kb7 Re8
36. Kc7 Re6 37. Rd8+ Re8 38. Rd5 (22774 kN)
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