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MadChess 2.0 Beta Build 038 (Killer Moves)

By Erik Madsen January 3, 2015 at 1:01 PM September 16, 2022 at 6:34 PM Code

I added killer moves to MadChess 2.0 Beta. Killer moves are quiet moves (not captures or pawn promotions) that cause a beta cutoff. Two killer moves are saved for each ply. They are searched immediately after captures and pawn promotions.

This added 61 Elo to the playing strength of MadChess 2.0 Beta.

MadChess 2.0                   2065 :    800 (+396,=136,-268),  58.0 %

vs.                                 :  games (   +,   =,   -),   (%) :   Diff,  SD, CFS (%)
BikJump v2.01                       :    100 (  36,  21,  43),  46.5 :    -26,  11,    0.8
Matheus-2.3                         :    100 (  40,  20,  40),  50.0 :     -7,  11,   27.3
Monarch 1.7                         :    100 (  38,  19,  43),  47.5 :    +14,  11,   90.3
BigLion 2.23w                       :    100 (  49,  15,  36),  56.5 :    +44,  12,  100.0
Sharper 0.17                        :    100 (  61,   5,  34),  63.5 :    +60,  11,  100.0
Faile 1.4                           :    100 (  52,  23,  25),  63.5 :    +85,  11,  100.0
Jabba13032012                       :    100 (  62,  14,  24),  69.0 :   +117,  11,  100.0
Roce 0.0390                         :    100 (  58,  19,  23),  67.5 :   +182,  11,  100.0

Feature	Category	Date	Rev¹	WAC²	Elo Rating³	Improvement
Killer Moves	Search	2015 Jan 03	38	275	2065	+61
Futility Pruning	Search	2014 Dec 29	37	256	2004	+54
Null Move Quiescence Recaptures	Search	2014 Dec 28	34	242	1950	+46
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	–

Subversion source code revision
Win At Chess position test, 3 seconds per position
Bullet chess, 2 min / game + 1 sec / move

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