Author(s): Jon Dart (USA)
Release Date: 2024-12-16
Language: C++
Protocol: UCI/XB
Repo Owner: jdart1
Repo URL: https://github.com/jdart1/arasan-chess
Repo URL: https://www.arasanchess.org/old_downld.shtml
Changes in Arasan 25.0:
- Use a single “Book variety” option to control move selection from the book
- Some changes to book move selection logic
- Fix Intel oneAPI compiler support. Add support for CSSPGO with Intel/clang.
- Fixes/updates to selfplay utility. Support output in the format used by bullet.
- Add SyzygyUse50MoveRule and SyzygyProbeDepth options for CECP
- Make NNUE usage non-optional. Fail on startup if network cannot be loaded.
- arasan.rc is no longer loaded by the engine, by default. Auto-loading (the prior behavior) can be enabled via the -a command-line option, or use -r to select a specific file.
- Make eval command evaluate current position, like Stockfish
- Change SyzygyTbPath option to SyzygyPath, for conformity to Stockfish and most other engines
- New network architecture and network
- Changes to history score computation
- Use capture history for move ordering
- Implement a parameter tuning framework for search parameters, tune some using Lakas (https://github.com/jdart1/Lakas)
- Changes to static null pruning, adjust margins
- Windows GUI sources are now included in the repo
- GUI can set some options formerly only settable via arasan.rc
There is also an update to the Arasan test suite, available here: https://arasanchess.org/testsuite.shtml.
Test results of version 25.0 against version 24.2, tc 1:0+0.8, 512MB, 8moves_v3.pgn book:
Elo: 19.13 +/- 6.86, nElo: 42.52 +/- 15.23
LOS: 100.00 %, DrawRatio: 79.50 %
Games: 2000, Wins: 260, Losses: 150, Draws: 1590, Points: 1055.0 (52.75 %)https://github.com/jdart1/arasan-chess/archive/refs/tags/v25.0.zip
https://github.com/jdart1/arasan-chess/archive/refs/tags/v25.0.tar.gz
https://arasanchess.org/arasan25.0.exe
https://arasanchess.org/arasan25.0.zip
https://arasanchess.org/arasan-linux-binaries-25.0.tar.gz
https://arasanchess.org/arasan25.0-m1.dmg
https://arasanchess.org/arasan25.0-intel.dmg