MadChess 2.0 Beta Build 032 (King Safety)

I added king safety evaluation to MadChess 2.0 Beta. Defects in king protection (missing pawn shield, semi-open files adjacent to king, squares near king attacked by enemy pieces) are counted, then used as an index into a non-linear piece coordination table.

It took me several attempts to calibrate the weights and the non-linear penalty, but eventually I found an improvement. This added 27 ELO to the playing strength of MadChess 2.0 Beta.

MadChess 2.0                   1904 :    800 (+233,=127,-440),  37.1 %

vs.                                 :  games (   +,   =,   -),   (%) :   Diff,  SD, CFS (%)
BikJump v2.01                       :    100 (   6,  18,  76),  15.0 :   -190,  12,    0.0
Matheus-2.3                         :    100 (  17,  18,  65),  26.0 :   -165,  12,    0.0
Monarch 1.7                         :    100 (  18,  15,  67),  25.5 :   -142,  13,    0.0
BigLion 2.23w                       :    100 (  29,  16,  55),  37.0 :   -107,  12,    0.0
Faile 1.4                           :    100 (  33,  19,  48),  42.5 :    -96,  10,    0.0
Sharper 0.17                        :    100 (  32,  18,  50),  41.0 :    -87,  12,    0.0
Jabba13032012                       :    100 (  46,   8,  46),  50.0 :    -28,  11,    0.5
Roce 0.0390                         :    100 (  52,  15,  33),  59.5 :    +49,  11,  100.0
Feature Category Date Build Number WAC1 ELO Rating2 Improvement
King Safety Evaluation 2014 Dec 24 32 225 1904 +27
Piece Mobility Evaluation 2014 Dec 16 29 225 1877 +64
Draw By Repetition Bug Evaluation 2014 Dec 10 27 225 1813 +47
Passed Pawns Evaluation 2014 Dec 09 26 225 1766 +72
Time Management Search 2014 Dec 08 25 231 1694 +24
Delay Move Generation
Aspiration Window Bug
Search 2014 Dec 02 23 231 1670 +44
MVV / LVA Move Order
Draw By Insufficient Material
Move List Overflow Bug
Search 2014 Dec 01 22 235 1626 +30
Tapered Evaluation
MG and EG Piece Location
Evaluation 2014 Nov 29 21 234 1596 +107
Alpha / Beta Negamax
Aspiration Windows
Quiescence, Hash
Material, Piece Squares
Baseline 2014 Nov 25 20 236 1489
  1. Win At Chess position test, 3 seconds per position
  2. Bullet chess, 2 min / game + 1 sec / move
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