Muse

Introduction

About 15 years after my first attempt to write a computer chess program on my first computer, an Atari ST, I finally wrote my very own chess program! It appeared in its first incarnation (version 0.899b) in 2003/2004. Due to a lack of time and commitment I gave up working on it, but 12 years later, I suddenly found some motivation again, and created a new version. Its second incarnation (0.95x) is quite a bit stronger than the previous one, but of course Muse is an amateur engine and there are lots of better chess engines out there.

The current version of Muse (0.95x) does most of the usual stuff:

• Negamax scout-style search with transposition tables
• Quiescence search with SEE (static exchange evaluator)
• Check generation in Quiescence
• Adaptive null-move pruning
• Late move reductions
• Futility pruning
• Check extensions
• Move ordering with killer and history moves
• Pawn hashing
• Opening Book (Courtesy of Berniman, author of Chesspresso) - thanks!

The todo list is long as always, but mostly consists of lots of testing, something I am not sure I will have the patience to do.

• More, or more relevant knowledge in the evaluation - a never-ending topic
• Tuning of evaluation parameters
• Tuning of search parameters (Null move, late move reductions, futility, qsearch...)
• The laws of chess (at the moment, 50-move-rule, and 3-fold repetition are not supported)
• Pondering
• Endgame tablebase access
• ....and much more!

Download and Installation

• Download Muse 0.953 and its readme file (62 KB).
• Download the Muse 0.899b engine and .ini file as a zipfile (117 KB).
• Download a small opening book as zipfile (575 KB).

Make sure that book.txt is in the same directory as the .exe file. Muse.ini is not necessary for Muse to work, but if you run it under Winboard you can set some options that you couldn't otherwise. Muse should work both as winboard and as UCI engine. However, the support of both protocols is far from complete.

Muse.ini

There are only a few options you can set in muse.ini. These are:

• hash X -- sets the hashtable size to X MB.
• resign 0/1 -- allows Muse to resign (1) or not (0)
• book 0/1 -- will make Muse use the book (1) or not (0)
• ponder 0/1 -- will allow Muse to ponder or not, only works under UCI for now!
• easymove 0/1 -- will allow Muse to play "easy" moves faster than normal moves

Test results for Muse 095

...will appear later

Test Results for Muse 0899b

I used to test Muse with the help of Arena and Winboard, free GUIs for chess engines. With Arena, I have it play tournaments with other engines, and solve test suites; mostly ECM98. With Winboard, I have Muse play on ICC.

• Muse 0.821 in ECM98: 495/770 solved at 5s/move on a 1.3GHz Pentium M
• Muse 0.821 playing on ICC on a P4 1.4GHz had a blitz rating of around 2400
• Muse 0.872 in ECM98: 538/770 solved at 5s/move on a 1.3GHz Pentium M
• Muse 0.872 was mostly above 2500 blitz rating on ICC (best: 2581), sometimes it drops below 2500 when it's abused or when good (C) accounts beat it up.
• Muse 0.888 in ECM98: 574/770 solved at 5s/move on a 1.4GHz Pentium M (my 1.3GHz laptop was stolen, so I have a faster one now...)
• Muse 0.888 on ICC was still usually somewhere between 2500 and 2600 (best: 2674).
• Muse 0.898 in ECM98: 577/770 solved at 5s/move on 1.4GHz Pentium M
• Muse 0.899 on ICC on an Athlon64 3000+ is usually somewhere between 2600 and 2700.
• Muse 0.899 in ECM98: 590/770 solved at 5s/move on a 1.4GHz Pentium M

I also used to run Nunn2 tournaments against other engines, 40 games at Blitz level 1 minute base + 5 seconds increment. Latest results:

• Muse 0.898 - Frenzee 1.46: 22.5-17.5
• Muse 0.898 - Gothmog 1.0 beta 10: 10.5-29.5
• Muse 0.899 - Frenzee 1.46: 24-16
• Muse 0.899 - Gothmog 1.0 beta 10: 16.5-23.5

Credits

I wrote Muse all by myself, but there are many people who helped in some way or other. Here's an incomplete list of people I'd like to thank:

Bernhard Seybold produced an opening book for Muse

Pradu Kannan wrote a magic move generator for bitboards, used in Muse 095 (0899b had my own move generator).

On CCC/talkchess, many people made/make interesting suggestions and comments, to name but a few: Bob Hyatt, Dieter Buerssner, Tord Romstad, Sune Fischer, Martin Sedlak and many more!

This page was last updated on April 10th, 2016