Author: Stuart Cracraft
Date: 15:00:14 01/08/99
Go up one level in this thread
Hi -- here's a 20 ply search by GNU Chess 5.0.
It starts out with a root score (evaluation at
top level of only 5) and gradually that increases
to 2/3 of a pawn.
The 20 ply search took about 6 1/2 minutes on the
SUN Ultra-5. Rate was about 64,000 nodes per second.
Reaching 2/3 of a pawn occurs at ply 18.
The program presently awards a small (8/100 of a pawn)
award for the presence of pawns on both sides in the
endgame. It's done this way:
#define GOODENDINGBISHOP 8
/* During the ending, a bishop is good with pawns on both side */
c = board.b[side][pawn] | board.b[xside][pawn];
if (ENDING && (c & (FileBit[0] | FileBit[1] | FileBit[2])) &&
(c & (FileBit[5] | FileBit[6] | FileBit[7])))
s += GOODENDINGBISHOP;
white
b . . . . . k .
. . . . . . . p
. . . . p . p P
. . . . P . P .
. . . . . . . .
. . . . . . . .
. . . . . . . .
N . . . . . K .
White (1) : depth 20
White (1) : go
Root score = 5 Phase = 8 Depth = 20
no book.
1. 25 1 5 Nb3
2& -15 1 26 Nb3 Bd5
2. -15 1 34 Nb3 Bd5
3& 8 1 83 Nb3 Bd5 Nc5
3. 8 1 150 Nb3 Bd5 Nc5
4& -3 2 414 Nb3 Bd5 Nc5 Kf7
4. -3 2 503 Nb3 Bd5 Nc5 Kf7
5& 9 3 1017 Nb3 Bd5 Nc5 Kf7 Kf2
5. 9 4 1340 Nb3 Bd5 Nc5 Kf7 Kf2
6& 8 7 2574 Nb3 Bd5 Nc5 Kf7 Kf2 Ke7
6. 8 8 2975 Nb3 Bd5 Nc5 Kf7 Kf2 Ke7
7& 24 13 5555 Nb3 Bd5 Nc5 Kf7 Kf2 Ke7 Ke3
7. 24 16 6880 Nb3 Bd5 Nc5 Kf7 Kf2 Ke7 Ke3
8& 24 31 15125 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bd5
8. 24 36 17584 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bd5
9& 32 55 29294 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bd5 Kd4
9. 32 65 34291 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bd5 Kd4
10& 32 96 54754 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bg2 Kd4 Bd5
10. 32 137 76893 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bg2 Kd4 Bd5
11& 32 199 116135 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bg2 Ne4 Bxe4
11& 39 255 148663 Nc2 Kf7 Ne3 Bf3 Kf2 Bh5 Nc4 Bg4 Ke3 Bf5 Nd6+
Ke7
11. 39 285 164000 Nc2 Kf7 Ne3 Bf3 Kf2 Bh5 Nc4 Bg4 Ke3 Bf5 Nd6+
Ke7
12& 39 378 226530 Nc2 Be4 Ne3 Bf5 Nc4 Be4 Kf2 Kf8 Ne3 Bf5 Nc4
Be4
12. 39 471 281879 Nc2 Be4 Ne3 Bf5 Nc4 Be4 Kf2 Kf8 Ne3 Bf5 Nc4
Be4
13& 47 687 409319 Nc2 Be4 Ne3 Bf5 Kf2 Kf7 Kf3 Ke7 Nc4 Kf8 Nd6
Ke7 Kf4 Bd3
13. 47 834 498372 Nc2 Be4 Ne3 Bf5 Kf2 Kf7 Kf3 Ke7 Nc4 Kf8 Nd6
Ke7 Kf4 Bd3
14& 43 1075 661455 Nc2 Be4 Ne3 Bf5 Nc4 Kf7 Nd6+ Ke7 Kf2 Bc2 Ke3
Bb3 Ke4 Bd5+ Kd4 Kd7 Ke3 Ke7 Kd3 Kd7 Ke3
14. 43 1369 844838 Nc2 Be4 Ne3 Bf5 Nc4 Kf7 Nd6+ Ke7 Kf2 Bc2 Ke3
Bb3 Ke4 Bd5+ Kd4 Kd7 Ke3 Ke7 Kd3 Kd7 Ke3
15& 39 2328 1338964 Nc2 Be4 Ne3 Bf5 Kf2 Kf7 Kf3 Ke8 Nc4 Bd3 Nd6+
Kd7 Kf4 Bf5 Ke3 Kc6 Kd4 Kd7 Ke3
15. 39 3436 1902797 Nc2 Be4 Ne3 Bf5 Kf2 Kf7 Kf3 Ke8 Nc4 Bd3 Nd6+
Kd7 Kf4 Bf5
16& 37 5548 3021869 Nc2 Be4 Ne3 Bf5 Kf2 Kf8 Kf3 Ke7 Nc4 Bc2 Ke3
Ba4 Nd6 Bc6 Kd3 Bg2 Kd4 Bd5
16. 37 8641 4933292 Nc2 Be4 Ne3 Bf5 Kf2 Kf8 Kf3 Ke7 Nc4 Bc2 Ke3
Ba4 Nd6 Bc6 Kd3 Bg2 Nc4 Bd5 Nb6 Bc6 Kd4
17& 39 9554 5522506 Nc2 Be4 Ne3 Bf5 Kf2 Kf8 Kf3 Ke7 Nc4 Bc2 Kf4
Kf7 Nd6+ Ke7 Kg3 Kd7
17& 40 13968 8538685 Kf2 Bd5 Nc2 Be4 Ne3 Bf5 Nc4 Be4 Nd6 Bc6 Nc4
Kf8 Kg3 Ke7 Ne3
17& 41 15728 9666294 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Kg3 Bh1 Kf4 Bg2
17. 41 15728 9666294 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Kg3 Bh1 Kf4 Bg2
18& 62 18365 11576816 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bg2 Kf4 Kf7 Nd7
Kg8 Nf6+ Kh8 Ke3 Bc6 Kd4 Bb7 Kd3 Ba6+ Ke4
Bb7+ Kd3
18. 62 19609 12523630 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bg2 Kf4
19& 62 22914 14697548 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bg2 Kf4
19. 62 25233 16355546 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bg2 Kf4
20& 62 33248 21490893 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bg2 Kf4 Bd5 Nd3
Kf7 Nf2 Kg8 Ng4 Kh8 Ke3 Bc6 Nf6 Bb7 Kd4 Bg2
Kd3 Bf1+ Ke4 Bc4 Kf4 Be2 Kg3 Bh5
20. 62 39365 25379355 Nb3 Kf7 Nc5 Ke7 Kf2 Bc6 Ke3 Bg2 Kf4
Time = 393.7 Rate=64471 Nodes=[24906850/472505/25379355] GenCnt=20459188
Eval=[1700714/5466533] RptCnt=154269 NullCut=55728 FutlCut=97741
Ext: Chk=488926 Recap=42446 Pawn=30541 OneRep=2808 Horz=3788 Thrt=0
Material=[350/350 : 650/650] Worst=[-52/-70]
Hash: Success=75% Collision=90% Pawn=99%
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Last modified: Thu, 15 Apr 21 08:11:13 -0700
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