Author: Brian Richardson
Date: 19:50:53 08/29/02
Go up one level in this thread
On August 29, 2002 at 21:24:32, Dann Corbit wrote:
>On August 29, 2002 at 20:40:44, David Hanley wrote:
>
>>Ok, i have my program working and fairly complete--it has all the rules in and
>>plays decent positional chess. I'm pleased.
>>
>>I implemented all the mechanisms that i think i'm supposed to--nullmove, hash
>>move first, then two killers, then winning static exchange moves sorted by
>>expected material win, then moves sorted by their history score. I sort moves
>>at the root with each iterative deepening.
>>
>>However, the branching factor seems 'off.' My branching factor seems to vary
>>between 4 and 7. For example, here's an 8 ply search from the opening position:
>>
>>Score: -53
>>Searched 414821 total nodes
>>Got 114215 hash hits (27 percent hits)
>>There were 240894 quiesce nodes
>>The pawn hash contains 17855 entries
>>Branching factor is 4.522705
>>
>>Here's a 6 ply search a bit later: (white just thought and chose e3)
>>
>>+---+---+---+---+---+---+---+---+
>>| R | N | | Q | K | B | | R |
>>+---+---+---+---+---+---+---+---+
>>| P | P | P | | P | P | P | P |
>>+---+---+---+---+---+---+---+---+
>>| | | | | | N | | |
>>+---+---+---+---+---+---+---+---+
>>| | | | P | | B | | |
>>+---+---+---+---+---+---+---+---+
>>| | | |*p | | | | |
>>+---+---+---+---+---+---+---+---+
>>| | |*n | |*p |*n | | |
>>+---+---+---+---+---+---+---+---+
>>|*p |*p |*p | | |*p |*p |*p |
>>+---+---+---+---+---+---+---+---+
>>|*r | |*b |*q |*k |*b | |*r |
>>+---+---+---+---+---+---+---+---+
>>Score: -44
>>Searched 134392 nodes
>>Got 27504 hash hits (20 percent hits)
>>There were 87728 quiesce nodes
>>The pawn hash contains 6098 entries
>>Branching factor is 5.999756
>>
>>
>>I guess i wonder if i'm fussing over nothing. Or perhaps if my search is broken
>>somehow. I tried turning off move sorting and launched a search from the
>>opening position. It seems to indicate to me that the move sorting is having a
>>big positive effect. Here's a six ply search from the opening position, no move
>>sorting:
>>
>>Score: -55
>>Searched 591677 nodes
>>Got 128337 hash hits (21 percent hits)
>>There were 395070 quiesce nodes
>>The pawn hash contains 31050 entries
>>Branching factor is 7.623291
>>
>>It took more nodes than the 8 ply search with sorting!
>>
>>Maybe i should be happy with my code, but i hear people talking of branching
>>factors like two and three. So maybe i should look for a bug.
>================================================
>Yace looked at less than ten percent of that many nodes:
Is move sorting turned off in Yace, GLC and Gnu for the depth = 6 searchs?
>================================================
>white ( 1): sd 6
>search depth=6
>white ( 1): go
>usetime = 9999999999.00, mintime = 9999999999.00 maxtime = 9999999999.00 tl
>9999999999.00 ml 0
> 1 0.025 0.27 1t 1.e4 {0}
> 20 0.030 0.27 1. 1.e4 {0}
> 42 0.037 0.00 2t 1.e4 e5 {0}
> 117 0.044 0.00 2. 1.e4 e5 {0}
> 296 0.050 0.19 3t 1.e4 d5 2.Nc3 {0}
> 382 0.057 0.19 3. 1.e4 d5 2.Nc3 {0}
> 917 0.065 0.00 4t 1.e4 d5 2.Nc3 Nf6 {0}
> 2708 0.075 0.00 4. 1.e4 d5 2.Nc3 Nf6 {0}
> 5475 0.088 0.18 5t 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd4 {0}
> 6798 0.098 0.19 5t+ 1.d4 d5 2.Nc3 Nf6 3.Nf3 {0}
> 6938 0.103 0.19 5t 1.d4 d5 2.Nc3 Nf6H 3.Nf3H {0}
> 9347 0.121 0.19 5. 1.d4 d5 2.Nc3 Nf6 3.Nf3 {0}
> 13968 0.138 0.00 6t 1.d4 d5 2.Nc3 Nf6 3.Nf3 Nc6 {0}
> 34240 0.210 0.00 6. 1.d4 d5 2.Nc3 Nf6 3.Nf3 Nc6 {0}
> 34240 0.214 0.00 6f. 1.d4 d5 2.Nc3 Nf6 3.Nf3 Nc6 {0}
>34240 Nodes, 24.82% Leavenodes, 160000 Nodes/sec
>27160 eval, 58.52% score, 98849 genmoves, 14.28% captures le 95/84
>ext: pawn 0, rcp 26, chk 226, repchk 60, null 0, prune 599
>htable: 28874 store, 0 rejected, 34372 probe, 28.1% f/p, 33.4% f/s
>entries 5416665 age 1 renew 0
>egtb probes 0, found 0 max_depth 14
>white ( 1): d4
>================================================
>GLC-218 shows an even more drastic difference:
>================================================
>>sd 6
>>go
> fen rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
> Game finished test: 0
> time limit 10.00 (1 moves left) max time limit 10.00
> Generating internal KP-K end-game table...
> Done (0.320 secs)
> Game stage: Opening
> Current eval: 0.000
> Ply Time Score Nodes Principal Variation
> 6 0.02 +0.000 6174 Nf3 Nf6 2. Nc3 Nc6 3. d3 e6
> 6 0.04 +0.000 12970 Nf3 Nf6 2. Nc3 Nc6 3. d3 e6
> local: t=0.05 nps=259404.0 n=12970 (37.2% / 62.8%) fh=91.7%
> total: t=0.05 nps=259404.0 n=12970 draws=0
> trans: probes=4826 hits=858 (17.78%) draft=342 (7.09%)
> tcuts: exact=7 (0.15%) upper=309 (6.40%) lower=9 (0.19%)
> tstor: exact=18 (1.52%) upper=920 (77.83%) lower=244 (20.64%)
> ext: check=25 recap=13 ppush=0 1rep=3 thrt=0
> q-moves: gen=2712 tested=2040 made/un=941 max-dep=5
> max eval diff: part-1=0.721 part-2=0.809
> !m Ng1-f3 0 1
>move g1f3
> time left 10.00
> -> Score=0 PV=Nf3 Nf6 2. Nc3 Nc6 3. d3 e6
> Game finished test: 0
>>
>
>
>
>================================================
>Gnu Chess:
>================================================
>GNU Chess 5.04aTE
>
>Transposition table: Entries=1024K Size=32768K
>Pawn hash table: Entries=16K Size=1024K
>White (1) : post
>White (1) : book off
>book now off.
>White (1) : sd 6
>Search to a depth of 6
>White (1) : go
>Thinking...
>Root = -35, Phase = 1 Depth = 6
>Ply Time Eval Nodes Principal-Variation
> 1+ 0.01 41 1 Nf3
> 1. 0.02 41 21 Nf3
> 2& 0.02 -10 61 Nf3 Nf6
> 2. 0.04 -10 99 Nf3 Nf6
> 3& 0.04 40 203 Nf3 Nf6 Nc3
> 3. 0.06 40 222 Nf3 Nf6 Nc3
> 4& 0.07 -10 376 Nf3 Nf6 Nc3 Nc6
> 4. 0.08 -10 869 Nf3 Nf6 Nc3 Nc6
> 5& 0.10 29 2001 Nf3 Nf6 Nc3 Nc6 e4
> 5. 0.12 29 3056 Nf3 Nf6 Nc3 Nc6 e4
> 6& 0.14 -10 5771 Nf3 Nf6 Nc3 Nc6 e4 e5
> 6. 0.21 -10 17175 Nf3 Nf6 Nc3 Nc6 e4 e5
>
>Time = 0.2 Rate=83407 Nodes=[15329/1846/17175] GenCnt=19137
>Eval=[4444/7463] RptCnt=0 NullCut=746 FutlCut=2442
>Ext: Chk=203 Recap=25 Pawn=167 OneRep=19 Horz=1 Mate=0 KThrt=19
>Material=[3600/3600 : 4400/4400] Lazy=[177/129] MaxPosnScore=[226/204]
>Hash: Success=25% Collision=6% Pawn=73%
>
>black KQkq
>r n b q k b n r
>p p p p p p p p
>. . . . . . . .
>. . . . . . . .
>. . . . . . . .
>. . . . . N . .
>P P P P P P P P
>R N B Q K B . R
>
>
>My move is : Nf3
>
>================================================
>Phalanx needs less than 10K nodes:
>================================================
>Depth=6, Value=31, Time=0.18, Last turn=0.00, Nodes=9829, N/s=54605
>PV = Pd2-d4 Pd7-d5 Ng1-f3 Nb8-c6 Pe2-e3 Ng8-f6
>my move is Pd2-d4
>1. ... d2d4
>[ black, 1 ]
>
>================================================
>Genesis:
>================================================
>White(1): bookoff
>opening book off.
>White(1): on
>depth time score variation
> 1-> 0.01 0.22 1. d2d4
> nodes 21 nps 2100 q 0% hhits 0%
> 2-> 0.02 0.00 1. d2d4 d7d5
> nodes 73 nps 7300 q 2% hhits 1%
> 3-> 0.04 0.18 1. d2d4 d7d5 2. g1f3
> nodes 204 nps 10200 q 3% hhits 19%
> 4-> 0.08 0.03 1. e2e4 g8f6 2. e4e5 f6e4
> nodes 1812 nps 45300 q 18% hhits 16%
> 5-> 0.15 0.17 1. e2e4 e7e5 2. d2d4 d7d5 3. g1f3 d5e4 4. f3e5
> nodes 3941 nps 56300 q 24% hhits 7%
> 6-> 0.60 0.01 1. d2d4 d7d5 2. c1e3 g8f6 3. b1c3
> nodes 34531 nps 76565 q 27% hhits 13%
>----------------------------------------------------------
>nodes 40582 time 0.60 nps 67524
>leaf 24179 q 10898 eval 29531
>null 4205 null-cut 2053
>hhits 5205 hexact 2751 hleaves 2751
>hput 7847 hoverwrites 0
>leaves 59% quiesc 26% null 10%
>null-cut 65% aspwin-suc 100%
>hhits 12% hoverwrites 0% husage 0%
>White(1): d2d4
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