HomeVersion historyInstructions PageDownloadsRelated LinksContact MeCredits


Ziggurat is written by me, but has a little public domain code in it.  In addition, a great body of work has preceeded Ziggurat, and I've used many of these ideas.  Here I wish to give credit to those whose worked I have used, and to those I have been inspired from.
Ziggurat uses the Mersenne Twister random number generator MT19937 from Takuji Nishimura and Matsumoto.  You can find their work at http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/ARTICLES/mt.pdf.
Ziggurat uses the ideas from Fruit in the creation of piece-square tables; that is, their automatic construction based on a smaller set of tunable variables.  The comparison of the piece square tables in Fruit and Rybka at https://webspace.utexas.edu/zzw57/rtc/eval/pst.html has been very enlightening.  I took many ideas from this; thanks to Fabien Letouzey for the Fruit program; I do not know who did the analysis on the above mentioned web page but it was very instructive; thank you.  I did not copy any actual code, but the way Ziggurat creates and uses piece square tables is based on how Fruit does it.  Look at the tuning variables to see how this works.  These are all in the ziggurat.ini file.
A very special thanks to the following individuals who have published the code for their chess programs so that others might learn from their work.  Although Ziggurat does not contain source code from these individuals or their work, it was often a great help to look and see how other world-class programs implemented particularly difficult features:
Crafty, By Dr. Robert Hyatt - http://www.cis.uab.edu/hyatt/
TSCP, by Tom Kerrigan - http://www.tckerrigan.com/Chess/TSCP
Stockfish, by Tord Romstad, Marco Costalba and Joona Kiiski - http://www.stockfishchess.com/
Thanks to Dan Corbit for the "silent but deadly" suite of test positions.
Special tanks to the following individuals, whose academic papers provided me with long and happy hours of trying to understand how the best chess programs work:
    Yngvi Bjornsson
    Michael Buro
    Dave Gomboc
    Robert Hyatt
    Akihiro Kishimoto
    Danny Kopec
    Liwu Li
    Tony Marsland
    Alexander Reinefeld
    Jonathan Schaeffer

Enter supporting content here