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--- computer_chess:engines:myrddin:index 2023/06/11 13:59
+++ computer_chess:engines:myrddin:index 2024/11/10 23:59 current
@@ Line 1: / Line 1: @@
 ===== Myrddin =====
-{{myrddin.jpg}}
+First of all, thanks very much to Ron Murawski for making this site available and hosting Myrddin's history here! =)
-First of all, thanks very much to Ron Murawski for making this site available and hosting Myrddin here! =)
+Myrddin 0.91 supports SMP via processes (up to 16 instances) and is about 300-350 ELO stronger than v0.90 at 1 CPU and a further 80 ELO stronger at 4 CPUs. This version has not been formally tested above 4 CPUs so it is unknown how well it will scale above 4 CPUs.
-Myrddin 0.90 supports SMP via processes (up to 16 instances) and is about 50 ELO stronger than v0.89 at 1 CPU and a further 80 ELO stronger at 4 CPUs. This version has not been formally tested above 4 CPUs so it is unknown how well it will scale above 4 CPUs.
 ==== Download ====
-Executable Package - [[https://www.dropbox.com/s/z2fkfkyxigohhp7/Myrddin%20090.rar?dl=0 | Myrddin 0.90]] (released 6/9/23, CCRL rating approximately 2650 at 1 CPU and 2730 at 4 CPUs)\\
+Executable Package - [[https://www.dropbox.com/scl/fi/fpbbdfrsn2bc2dqa8gsrv/Myrddin-091.rar?dl=0 | Myrddin 0.91]] (released 10/20/24, CCRL rating estimated at 2975 at 1 CPU and 3055 at 4 CPUs)\\
 Source Code - [[https://github.com/JVMerlino/Myrddin | Myrddin Source]]
 == Old versions ==
-[[https://www.dropbox.com/s/1ksfgbrtnpahg3o/Myrddin%20089.rar?dl=0 | Myrddin 0.89]] (released 6/3/22, CCRL rating of 2597 at 1 CPU)\\
+[[https://www.dropbox.com/s/z2fkfkyxigohhp7/Myrddin%20090.rar?dl=0 | Myrddin 0.90]] (released 6/9/23, CCRL rating 2627 at 1 CPU and estimated at 2710 at 4 CPUs)\\
-[[https://www.dropbox.com/s/v3amg3x4kkpjwqk/Myrddin%20088.rar?dl=0 | Myrddin 0.88]] (released 7/18/21, CCRL rating of 2560 at 1 CPU and 2629 at 4 CPUs)\\
+[[https://www.dropbox.com/s/1ksfgbrtnpahg3o/Myrddin%20089.rar?dl=0 | Myrddin 0.89]] (released 6/3/22, CCRL rating of 2587 at 1 CPU)\\
-{{myrddin087.rar | Myrddin 0.87}} (released 1/25/15, CCRL rating of 2399 at 1 CPU and 2482 at 4 CPUs)\\
+[[https://www.dropbox.com/s/v3amg3x4kkpjwqk/Myrddin%20088.rar?dl=0 | Myrddin 0.88]] (released 7/18/21, CCRL rating of 2545 at 1 CPU and 2621 at 4 CPUs)\\
-{{myrddin086-ja.zip | Myrddin 0.86}} (released 12/21/12, CCRL rating of 2365)\\
+{{myrddin087.rar | Myrddin 0.87}} (released 1/25/15, CCRL rating of 2365 at 1 CPU and 2461 at 4 CPUs)\\
+{{myrddin086-ja.zip | Myrddin 0.86}} (released 12/21/12, CCRL rating of 2328)\\
 This package contains Windows32/64, Linux32/64, & Android executables compiled by [[http://jim-ablett.co.de/ | Jim Ablett]], and a Mac executable compiled by [[http://predateur-chess.blogspot.com | Julien Marcel]], author of the Prédateur chess engine.\\
-{{myrddin085.rar | Myrddin 0.85}} (released 5/3/11, CCRL rating of 2223)\\
+{{myrddin085.rar | Myrddin 0.85}} (released 5/3/11, CCRL rating of 2171)\\
-{{myrddin084.rar | Myrddin 0.84}} (released 9/17/10, CCRL rating of 2115)\\
+{{myrddin084.rar | Myrddin 0.84}} (released 9/17/10, CCRL rating of 2052)\\
-{{myrddin083.rar | Myrddin 0.83}} (released 2/22/10, CCRL rating of 2010)\\
+{{myrddin083.rar | Myrddin 0.83}} (released 2/22/10, CCRL rating of 1938)\\
-{{myrddin082.rar | Myrddin 0.82}} (released 9/26/09, estimated CCRL rating of 1915)\\
+{{myrddin082.rar | Myrddin 0.82}} (released 9/26/09, estimated CCRL rating of 1875)\\
-{{myrddin_alpha_2.rar | Myrddin 0.81}} (released 5/26/09, estimated CCRL rating of 1550)\\
+{{myrddin_alpha_2.rar | Myrddin 0.81}} (released 5/26/09, estimated CCRL rating of 1510)\\
-{{myrddin_alpha_1.rar | Myrddin 0.80}} (released 3/9/09, estimated CCRL rating of 1250)\\
+{{myrddin_alpha_1.rar | Myrddin 0.80}} (released 3/9/09, estimated CCRL rating of 1220)\\
 ----
 ==== Release Notes ====
-Myrddin 0.90 -- 6/9/23
+Myrddin 0.91 -- 10/20/24
 Myrddin is a winboard-compliant chess engine to a reasonable degree. It supports protover 1 primarily to support the Chessmaster interface, and also protover 2.
-The 64-bit version of Myrddin should play approximately 2650 ELO against chess engines at 1 CPU (using CCRL rating), and probably 100 points higher against humans. This is an improvement of about 50 points compared to the previous release. Myrddin should play about 80 points stronger at 4 CPU.
+The 64-bit version of Myrddin should play approximately 2975 ELO against chess engines at 1 CPU (using CCRL rating), and probably 100 points higher against humans. This is an improvement of about 300-350 points compared to the previous release. Myrddin should play about 80 points stronger at 4 CPU.
 The following winboard commands are supported:
@@ Line 74: / Line 73: @@
 ====General Notes====
--- Myrddin's "Very Lazy SMP" implementation uses (N-1) child processes to fill the transposition, eval and pawn hash tables so the parent process can search deeper in the same amount of time. I believe Myrddin is the only engine that has implemented SMP with this method (and probably rightly so!).\\
+-- Myrddin uses an "NNUE-like" evaluation method created by David Carteau called [[https://github.com/david-carteau/cerebrum | "Cerebrum"]]. David also wrote the Orion chess engine.\\
+-- Myrddin's "Very Lazy SMP" implementation uses (N-1) child processes to fill the transposition and eval hash tables so the parent process can search deeper in the same amount of time. I believe Myrddin is the only engine that has implemented SMP with this method (and probably rightly so!).\\
 -- Myrddin uses Pradyumna Kannan's [[http://www.pradu.us/old/Nov27_2008/Buzz/ | magicmoves]] code for move generation of sliding pieces.\\
--- Myrddin uses a tapered eval which was tuned using a very rudimentary Texel tuning system.\\
+-- Myrddin supports the [[https://github.com/michiguel/Gaviota-Tablebases | Gaviota Endgame Tablebases]].\\
 -- Search is basic alpha/beta, with typical extensions and reductions.\\
 -- All user-modifiable parameters are supported in the INI file, an example of which is included in the download.\\
@@ Line 110: / Line 110: @@
 ==== Test Suite Results ====
-All results are for the 64-bit version of 0.89 using 1GB hash and 5-man Gaviota tablebases. The tests are run on an AMD Ryzen 5 3.6GHz machine at one CPU.
+All results are for version 0.91 using 1GB hash and 5-man Gaviota tablebases. The tests are run on an AMD Ryzen 5 3.6GHz machine at one CPU.
 == WAC (Win at Chess) ==
-positions at 5s per position. Almost exclusively tactical positions, many leading to mate. Myrddin finds 297 correct moves within the time limit. Regarding the three missed positions (230, 256, 293), only #256 is found within 15 seconds. The other two are not found within 30 seconds. This suite can be found [[http://www.bergbomconsulting.se/chess/epdfiles/wac.epd|here]].
+positions at 5s per position. Almost exclusively tactical positions, many leading to mate. Myrddin finds 297 correct moves within the time limit. Regarding the three missed positions (224, 247, 293), only #246 is not found within 10 seconds. This suite can be found [[http://www.bergbomconsulting.se/chess/epdfiles/wac.epd|here]].
 == Strategic Test Suite ==
-A series of (currently, but occasionally expanding) 14 individual suites of 100 positions each, primarily intending to test positional knowledge such as square vacancy, proper recapturing, pawn advancement, control of the center, etc. At 10s per move, Myrddin gets 952 out of 1400 positions correct. This suite is also interesting because it contains "partial credit". In other words, you can still get some points by choosing moves other than the optimal. Myrddin gets 10,914 out of 14,000 points if partial credit is included. You can download this test suite [[http://sites.google.com/site/strategictestsuite|here]].
+A series of (currently, but occasionally expanding) 14 individual suites of 100 positions each, primarily intending to test positional knowledge such as square vacancy, proper recapturing, pawn advancement, control of the center, etc. At 10s per move, Myrddin gets 952 out of 1400 positions correct. This suite is also interesting because it contains "partial credit". In other words, you can still get some points by choosing moves other than the optimal. Myrddin gets 11,606 out of 14,000 points if partial credit is included. You can download this test suite [[http://sites.google.com/site/strategictestsuite|here]].
 == O'Kelly ==
-positions at 10s per position. Combinative middlegame and endgame suite. Myrddin finds 136 positions within the time limit. You can download this test suite [[http://www.horizonchess.com/Download.html|here]].
+positions at 10s per position. Combinative middlegame and endgame suite. Myrddin finds 139 positions within the time limit. You can download this test suite [[http://www.horizonchess.com/Download.html|here]].
 == Eigenmann Endgame Test ==
-positions at 10s per position. Myrddin does not do very well at this suite, getting only 41 correct moves within the time limit. You can download this test suite [[http://computer-chess.org/doku.php?id=computer_chess:wiki:download:epd_contents|here]].
+positions at 10s per position. Myrddin does not do very well at this suite, getting only 51 correct moves within the time limit. You can download this test suite [[http://computer-chess.org/doku.php?id=computer_chess:wiki:download:epd_contents|here]].
 == IQ 8.1 ==
-positions at 10s per position. Challenging tactical suite. Myrddin finds 158 positions within the time limit. You can download this test suite [[http://www.horizonchess.com/Download.html|here]].
+positions at 10s per position. Challenging tactical suite. Myrddin finds 165 positions within the time limit. You can download this test suite [[http://www.horizonchess.com/Download.html|here]].
 ====FULL DISCLOSURE====
@@ Line 131: / Line 131: @@
 ====Version/Change List====
+== Version 0.91 (10/20/24) ==
+-- Added NNUE probing code by David Carteau (Orion / Cerebrum). All code related to the HCE has been removed, as well as the pawn hash\\
+-- Network created by me using games from CCRL, Lichess, and Myrddin testing (both self-play and against other engines)\\
+-- Fixed a rare bug that could cause the best move from the previous iteration to not be the first move searched\\
+-- If perft or divide are called with no parameters, the default depth will be one (and Myrddin will no longer crash)\\
+== Version 0.90 (6/9/23) ==
+-- Fixed two bugs in SEE (stopped the calculation if the first capture was of equal value, and failed to include Kings in the calculation)\\
+-- Fixed a bug that could cause a save to the hash table even if there was no best move\\
+-- Tuned PST files for the first time, and re-tuned all other eval terms\\
+-- Captures with negative SEE value can now be reduced\\
+-- IID is now more aggressive in its depth reduction and can be applied in PV nodes\\
+-- LMR reduction is now one depth less for PV nodes\\
+-- No longer limiting the number of extensions for a single branch\\
+-- Reduced the number of aspiration windows before performing a full-width search from six to two\\
+-- Fixed a rare bug such that if a tt probe or IID returned an underpromotion it would not be moved to the front of the movelist\\
+-- Fixed an issue when receiving the "force" command while pondering, which can happen with some GUIs\\
+-- Modified the compiler options for magicmoves to improve perft results by 5%.\\
+-- Various minor optimizations\\
+-- Added "see" command to return the SEE value of a capture on the current position - example usage "see d4 e5"\\
+-- Added "rpt" command to run a brief perft test (perft uses bulk counting)\\
+-- Removed "-64" from version string as there is no longer a 32-bit version\\
 == Version 0.89 (6/3/22) ==

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