Author: Paulo Soares
Date: 00:00:04 12/10/99
Go up one level in this thread
On December 09, 1999 at 20:14:01, Dann Corbit wrote:
>On December 09, 1999 at 18:45:42, Paulo Soares wrote:
>>I think that are some lines that programs can't see even at
>>depth 20.
>Absolutely. Any move where the "payoff" is 10 full moves ahead will take 20
>plies to see. And if the payoff is farther, the computer may not make the right
>choice until the move is seen. Often, however, there is a simple reason why a
>choice was not seen. More often than not when the computer analysis is deep
>enough to see the benefit drawn in the human analysis, one of the following
>problems exists:
>{calling the position with a clear benefit the final board position:}
>0. The final board position requires an intermediate positional move.
>1. The final board position requires a deep sacrifice.
>2. There is a zugzwang position between the final board position and the
>current position.
>3. The stated move is wrong {happens more often than you might think}.
Look for the line below, possibly the best, or less bad, for black. After 14
plies I placed Rebel Century (it could be another program ) to analyze the
position, you can see that the evaluation is low.
White wins this position, but in what item(0,1,2 or3)would you place the
position?
1. Bxh7+ Kxh7 2. Qh5+ Kg8 3. Rg3 Bf8 4. Bg5 Qc8 5. Rc1 (5. Bf6 Qc2!?) 5...
Nc6 6. Bf6 Nxd4 7. Rxc8 Raxc8
Position after 7....Raxc8:
2r1rbk1/1p3pp1/p3pB2/3pP2Q/P2n4/6RP/1P3PP1/6K1 w - - 0 8
PIII-450, HT=60Mb, Default settings:
+---+---+---+---+---+---+---+---+ ComeDann
8 | | | *R| | *R| *B| *K| |
+---+---+---+---+---+---+---+---+ 00:00:00 00:00:00
7 | | *p| | | | *p| *p| |
+---+---+---+---+---+---+---+---+
6 | *p| | | | *p| B | | | Time infinite
+---+---+---+---+---+---+---+---+ Hash 60 Mb
5 | | | | *p| p | | | Q | Engine Rebel Century
+---+---+---+---+---+---+---+---+ Personality Rebel Century
4 | p | | | *N| | | | | anti-GM Off
+---+---+---+---+---+---+---+---+ System Tiger Off
3 | | | | | | | R | p | Combination Off
+---+---+---+---+---+---+---+---+ Style Normal
2 | | p | | | | p | p | | Strength Strongest
+---+---+---+---+---+---+---+---+ Search Normal Search
1 | | | | | | | K | |
+---+---+---+---+---+---+---+---+
a b c d e f g h
2r1rbk1/1p3pp1/p3pB2/3pP2Q/P2n4/6RP/1P3PP1/6K1 w - -
00:00:00 1.00 -0.43 1.Bxg7 Bxg7
00:00:00 1.06 1.67 1.Rd3 gxf6 2.Rxd4
00:00:00 1.08 1.86 1.a5
00:00:00 1.11 2.08 1.b4
00:00:00 2.00 1.68 1.b4 Rc2 2.Rg4 Rc4 3.Rg3 Rxb4
00:00:00 2.05 1.71 1.b3 Rc1+ 2.Kh2
00:00:00 3.00 1.16 1.b3 Rc1+ 2.Kh2 Nf5 3.Rg4
00:00:00 3.01 1.19 1.b4 Rc1+ 2.Kh2 Rec8 3.f4
00:00:00 3.02 1.41 1.f4 Rc2 2.Kh2 Rxb2
00:00:00 3.04 1.42 1.Kh2 Nf5 2.Rg4 Rc2 3.Kg1 Rxb2
00:00:00 3.09 1.64 1.Rg4 Rc4 2.Rg3 Rxa4
00:00:00 4.00 1.54 1.Rg4 Nb3 2.g3 Rc2 3.f3 Rxb2
00:00:01 5.00 1.42 1.Rg4 Nf5 2.Kh2 Rc2 3.Kg1 Rxb2
00:00:02 6.00 1.16 1.Rg4 Nf5 2.b3 Rc1+ 3.Kh2 Rec8 4.b4
00:00:05 7.00 1.09 1.Rg4 Nf5 2.b4 Be7 3.b5 Bxf6 4.exf6
g6 5.bxa6 (3)
00:00:08 7.12 1.14 1.Rc3 Nf5 2.Rxc8 Rxc8 3.Bg5 g6
00:00:10 8.00 1.09 1.Rc3 Nf5 2.Bg5 Bb4 3.Rxc8 Rxc8
4.Qd1 Rc4 5.Qd3 (9)
00:00:22 9.00 1.05 1.Rc3 Nf5 2.Bg5 Bb4 3.Rxc8 Rxc8
4.Qd1 a5 5.Qb3 Nd4 6.Qd3 (18)
00:00:57 10.00 1.11 1.Rc3 Nf5 2.Bg5 Bb4 3.Rxc8 Rxc8
4.Qd1 Rc4 5.Kh2 Be7 (33)
00:02:07 11.00 1.08 1.Rc3 Nf5 2.Bg5 Bb4 3.Rxc8 Rxc8
00:06:34 12.00 1.11 1.Rc3 Nf5 2.Bg5 Bb4 3.Rxc8 Rxc8
4.Qd1 (196)
Positions : 99.105.320
Nodes per second : 131.091
Extensions (checks) : 4.276.716 (4%)
Extensions (captures) : 952.553 (0%)
Extensions (king safety) : 354.070 (0%)
Extensions (on depth) : 3.858.925 (3%)
Extensions (remaining) : 403.564 (0%)
Extensions (total) : 9.845.828 (9%)
Hash Table : 1.542.248 1.193.742 (99%)
Average depth : 13
Deepest depth : 41
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Last modified: Thu, 15 Apr 21 08:11:13 -0700
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