Author: Robert Hyatt
Date: 10:07:21 08/10/04
Go up one level in this thread
On August 09, 2004 at 14:26:18, Stuart Cracraft wrote:
>Sorry, the posted position was in error. It is:
>
>>[D]r1bqkb1r/2pp1ppp/p1n2n2/1p2p3/4P3/1B3N2/PPPP1PPP/RNBQ1RK1 b q - 4 1
>
>On August 09, 2004 at 14:25:30, Stuart Cracraft wrote:
>
>>[D]r1bqkb1r/2pp1ppp/p1n2p2/1p2p3/4P3/1B3N2/PPPP1PPP/RNBQ1RK1 b q - 4 1
>>
>>I don't know if I filled in the castle flags right but in this position
>>black still has both rights left.
>>
>>The question is, if your program values bishops more than knights,
>>how do you prevent it from playing Na5 to capture the White Bishop
>>but then giving up the pawn at e5 (since the capture Nxe4 by black
>>is unplayable). (e.g. 1. ... Na5 2. Nxe5 Nxb3 3. ab)
>>
>>I've searched this to 10 full ply with unlimited quiescence
>>and it still can't see that Na5 is bad.
>>
>>It would help if some people posted their searches and mention
>>how they avoid this kind of issue.
>>
>>My search:
>>
>>Alpha=-255 Beta=245 Maxdepth=99 MaxTime=9999999
>> 1/11> c6a5 0.00 245 68 c6a5
>> 1/11 f6e4 0.01 1026 159 f6e4
>> 2/15 f6e4 0.01 1008 946 f6e4 f1e1
>> 3/17< f6e4 0.02 758 4181 f6e4 d2d4 e5d4
>> 3/20 f6e4 0.04 75 7143 f6e4 b3d5 e4f6
>> 4/30 f6e4 0.13 75 24970 f6e4 b3d5 e4f6 d5c6
>> 5/34 c6a5 0.50 57 104715 c6a5 f1e1 a5b3 a2b3 c8b7
>> 6/34 c6a5 1.22 45 256985 c6a5 f1e1 a5b3 a2b3 c8b7 b1c3
>> 7/42 c6a5 4.31 32 889215 c6a5 f3e5 a5b3 c2b3 f8d6 d2d4 f6e4
>> 8/51 c6a5 24.86 19 5021946 c6a5 f3e5 a5b3 c2b3 d8e7 d2d4 d7d6 e5f3
>> 9/54 c6a5 115.27 19 19483875 c6a5 f3e5 a5b3 c2b3 d8e7 d2d4 d7d6 e5f3
>>10/54 c6a5 264.28 26 44999682 c6a5 f1e1 a5b3 a2b3 c8b7 d2d4 f6e4 b1d2 d7d5
>
>>
>>Stuart
The output above looks broken. Why not just take the pawn. Here is Crafty
after I play Na5 as black:
1 0.09 0.47 2. Nxe5 Nxb3 3. axb3 Nxe4
1-> 0.09 0.47 2. Nxe5 Nxb3 3. axb3 Nxe4
2 0.09 0.47 2. Nxe5 Nxb3 3. axb3 Nxe4
2-> 0.09 0.47 2. Nxe5 Nxb3 3. axb3 Nxe4
3 0.09 0.47 2. Nxe5 Nxb3 3. axb3 Nxe4
3-> 0.09 0.47 2. Nxe5 Nxb3 3. axb3 Nxe4
4 0.10 0.61 2. Nxe5 Nxb3 3. axb3 Bd6 4. d4 Bxe5
5. dxe5 Nxe4
4-> 0.10 0.61 2. Nxe5 Nxb3 3. axb3 Bd6 4. d4 Bxe5
5. dxe5 Nxe4
5 0.10 0.61 2. Nxe5 Nxb3 3. axb3 Bd6 4. d4 Bxe5
5. dxe5 Nxe4
5-> 0.10 0.61 2. Nxe5 Nxb3 3. axb3 Bd6 4. d4 Bxe5
5. dxe5 Nxe4 (s=2)
6 0.10 0.61 2. Nxe5 Nxb3 3. axb3 Bd6 4. d4 Bxe5
5. dxe5 Nxe4
6-> 0.11 0.61 2. Nxe5 Nxb3 3. axb3 Bd6 4. d4 Bxe5
5. dxe5 Nxe4 (s=2)
7 0.11 0.80 2. Nxe5 Nxb3 3. axb3 Bd6 4. d4 Bb7
5. f3 O-O
7-> 0.12 0.80 2. Nxe5 Nxb3 3. axb3 Bd6 4. d4 Bb7
5. f3 O-O (s=2)
8 0.15 0.85 2. Nxe5 Nxb3 3. axb3 d6 4. Nf3 Be6
5. e5 Ne4 6. d4
8-> 0.17 0.85 2. Nxe5 Nxb3 3. axb3 d6 4. Nf3 Be6
5. e5 Ne4 6. d4
9 0.22 0.65 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nb4 Nxe4 6. d3 c5
9-> 0.35 0.65 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nb4 Nxe4 6. d3 c5 (s=3)
10 0.44 0.97 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nb4 Be7 6. d4 O-O 7. Nc3 (s=2)
10-> 0.54 0.97 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nb4 Be7 6. d4 O-O 7. Nc3 (s=2)
11 0.70 0.78 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nb4 Be7 6. d4 O-O 7. Nc3 Bb7
11-> 2.44 0.78 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nb4 Be7 6. d4 O-O 7. Nc3 Bb7 (s=4)
12 3.03 0.83 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nd4 Be7 6. Qf3 O-O 7. Nc3 b4 8.
e5 (s=3)
12-> 6.44 0.83 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nd4 Be7 6. Qf3 O-O 7. Nc3 b4 8.
e5 (s=5)
13 10.00 0.88 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nb4 Be7 6. Nc3 O-O 7. Qf3 Bb7 8.
d4 Qg4 <HT> (s=4)
13-> 18.39 0.88 2. Nxe5 Nxb3 3. axb3 d6 4. Nc6 Qd7
5. Nb4 Be7 6. Nc3 O-O 7. Qf3 Bb7 8.
d4 Qg4 <HT> (s=4)
14 31.39 0.82 2. Nxe5 Nxb3 3. axb3 Bb7 4. d4 Be7
5. f3 d6 6. Nd3 O-O 7. c4 c5 8. cxb5
axb5 9. Rxa8 Bxa8 (s=3)
14-> 55.88 0.82 2. Nxe5 Nxb3 3. axb3 Bb7 4. d4 Be7
5. f3 d6 6. Nd3 O-O 7. c4 c5 8. cxb5
axb5 9. Rxa8 Bxa8 (s=3)
15 1:28 0.80 2. Nxe5 Nxb3 3. axb3 Be7 4. d4 O-O
5. f3 d6 6. Nc6 Qd7 7. Nxe7+ Qxe7 8.
Bg5 h6 9. Bxf6 Qxf6 10. Nc3 Re8 (s=2)
15-> 3:00 0.80 2. Nxe5 Nxb3 3. axb3 Be7 4. d4 O-O
5. f3 d6 6. Nc6 Qd7 7. Nxe7+ Qxe7 8.
Bg5 h6 9. Bxf6 Qxf6 10. Nc3 Re8 (s=4)
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