about gnuchess

[Li, Chendong]

Dear Sir,

I am very interested in gnuchess and I want know more information about it. 
Could you please tell me where I could find more detailed documentation about 
gnuchess. I have read the the file eval.c, but I am still not clear about the 
how the evaluation function works for a specified scenario.  Could you please 
tell me how the scoring algorithm of gnuchess works? How does the program 
evaluate the each ply? I want to understand the how the gnuchess gets the score 
(column of Eval) in the following form. Could you tell me where I could find 
the information about  all these parameters, like what is the meaning of 
"Pawn=64%" ? Thank you very much! I appreciate it!

Root = -10, Phase = 1 Depth = 6
Ply   Time     Eval      Nodes   Principal-Variation
 1.   0.00     62        20      e4
 2&   0.00    -10        60      e4 e5
 2.   0.00    -10       133      e4 e5
 3&   0.00     34       397      e4 d5 Nc3 dxe4 Nxe4
 3&   0.00     41       553      d4 d5 Nf3
 3.   0.00     41       631      d4 d5 Nf3
 4&   0.00    -10       872      d4 d5 Nf3 Nf6
 4&   0.01     -3      2217      e4 Nf6 Nc3 d5 exd5 Nxd5
 4.   0.01     -3      2583      e4 Nf6 Nc3
 5&   0.03    -10      7612      e4 d5 exd5 Qxd5 Nc3 Qe5+ Be2
 5&   0.04     13      9514      d3 d5 Nc3 Nf6 Nf3
 5&   0.04     40     12761      d4 d5 Nf3 Nf6 Nc3
 5.   0.05     40     14715      d4 d5 Nf3 Nf6 Nc3
 6&   0.07    -10     19152      d4 d5 Nf3 Nf6 Nc3 Nc6
 6&   0.16     -9     48987      e4 Nc6 d4 Nf6 d5
 6.   0.16     -9     48987      e4 Nc6 d4 Nf6 d5

Time = 0.2 Rate=297245 Nodes=[44779/4208/48987] GenCnt=49817
Eval=[15547/21899] RptCnt=0 NullCut=1313 FutlCut=3679
Ext: Chk=813 Recap=169 Pawn=269 OneRep=30 Horz=12 Mate=0 KThrt=35
Material=[3600/3600 : 4400/4400] Lazy=[191/186] MaxPosnScore=[274/238]
Hash: Success=20% Collision=87% Pawn=64%

Have a nice day! 

Best wishes, 
Sincerely, 
Chendong 
___________
Computer Science Department
Texas Tech University 
806.742.3513