Arasan 25.3

[jdart]

Arasan 25.3 is available from https://arasanchess.org.

Changes in Arasan 25.3:
1) Increase L1 size to 1792
2) New network, trained on 6B+ lc0 + selfplay games
3) Fix training script to sync with recent bullet updates
4) More changes to book selection logic
5) Omit positions from book with blunder eval or only losses
6) Code cleanup, especially in the SIMD code
7) Fix incorrect filtering of tablebase moves at root
8) Update to latest Fathom
9) Bug fixes involving handling of search statistics
10) Ponder option fixes. Set ponder off by default.
11) Fixes to CMakeLists.txt
12) import lichess-org/chess-openings for ECO coding

This has a significant, but not large, strength increase compared to the last release.

[jshriver]

Congratulations, compiling it as I write this.

[chessica]

Arasan 25.3 is available from https://arasanchess.org.

Changes in Arasan 25.3:
1) Increase L1 size to 1792
2) New network, trained on 6B+ lc0 + selfplay games
3) Fix training script to sync with recent bullet updates
4) More changes to book selection logic
5) Omit positions from book with blunder eval or only losses
6) Code cleanup, especially in the SIMD code
7) Fix incorrect filtering of tablebase moves at root
8) Update to latest Fathom
9) Bug fixes involving handling of search statistics
10) Ponder option fixes. Set ponder off by default.
11) Fixes to CMakeLists.txt
12) import lichess-org/chess-openings for ECO coding

This has a significant, but not large, strength increase compared to the last release.

76828*1*----------------------Starte Motor 1 Arasanx-64-avx512----------------------
76828*1*Configured Engine 1 Type: UCI
76828*1*Engine 1 dir: C:\Program Files\arena_3.5.1\Engines\arasan25.3
76828*1*Engine 1 commandline: "C:\Program Files\arena_3.5.1\Engines\arasan25.3\arasanx-64-avx512.exe"
76938*1*Child Process Prio Adj: PID 11544 conhost.exe
76938*1*Engine 1 ProcessID: 7404
76953*1*Engine 1 Prio:32 ThreadPrio:0
76984 <first : Arasan 25.3 Copyright 1994-2025 by Jon Dart. All Rights Reserved.
76984 >first : uci
76984 <first : id name Arasan 25.3
76984 <first : id author Jon Dart
76984 <first : option name Hash type spin default 32 min 4 max 64000
76984 <first : option name Ponder type check default false
76984 <first : option name Contempt type spin default 0 min -200 max 200
76984 <first : option name Use tablebases type check default false
76984 <first : option name SyzygyPath type string default syzygy
76984 <first : option name SyzygyUse50MoveRule type check default true
76984 <first : option name SyzygyProbeDepth type spin default 4 min 0 max 64
76984 <first : option name MultiPV type spin default 1 min 1 max 10
76984 <first : option name OwnBook type check default true
76984 <first : option name BookPath type string default C:\Program Files\arena_3.5.1\Engines\arasan25.3\book.bin
76984 <first : option name Book variety type spin default 50 min 0 max 100
76984 <first : option name Threads type spin default 1 min 1 max 512
76984 <first : option name Position learning type check default false
76984 <first : option name Learning file type string default C:\Users\Privat\AppData\Roaming\Arasan\arasan.lrn
76984 <first : option name UCI_LimitStrength type check default false
76984 <first : option name UCI_Elo type spin default 3450 min 1000 max 3450
76984 <first : option name NNUE file type string default arasanv5-20251222.nnue
76984 <first : option name Move overhead type spin default 30 min 0 max 1000
76984 <first : uciok
76984 >first : setoption name Hash value 1024
76984 >first : setoption name BookPath value C:\Program Files\arena_3.5.1\Engines\arasan25.3
76984 >first : setoption name Learning file value C:\Users\Privat\AppData\Roaming\Arasan\arasan.lrn
77000*1*Child Process Prio Adj: PID 11544 conhost.exe
77000 >first : isready
77234 <first : loaded network from file C:\Program Files\arena_3.5.1\Engines\arasan25.3\arasanv5-20251222.nnue
77234 <first : info string warning: opening book not found or invalid
77234 <first : info string warning: opening book not found or invalid
77234 <first : readyok

[peter]

Arasan 25.3 is available from https://arasanchess.org.

Thanks for the new version!
With the known 256 and 30"/position:

Code: Select all

    Program                                    Elo   +/-  Matches  Score   Av.Op.   S.Pos.   MST1    MST2   RIndex

  1 RemsM-091224-8t-26-4-2000                : 3583    2  42730    62.1 %   3497   218/256    3.3s    7.3s   0.66
  
 14 Stockfish17.1-8t-MuPV4-avx512            : 3550    2  40916    57.4 %   3498   195/256    4.3s   10.4s   0.56
 
 18 Lc0v0.32.0-rc2-1740-MuPV4                : 3546    2  39868    56.8 %   3499   193/256    4.8s   11.0s   0.57
 
 30 PlentyChess7.0.22-8t-MuPV4               : 3539    2  39564    55.8 %   3499   181/256    3.8s   11.4s   0.54

 37 Lc0v0.32.0-dev-1740-MuPV1                : 3538    2  39182    55.5 %   3500   180/256    4.0s   11.7s   0.56
 
 45 Stockfish-251014-8t-MuPV4                : 3534    2  39756    55.2 %   3499   183/256    4.6s   11.8s   0.52

 56 Stockfish-TI-251109-8t-MuPV4             : 3531    2  38911    54.6 %   3499   174/256    3.7s   12.2s   0.53

 70 Obsidian-16.15-8t-Co100-MuPV4            : 3522    2  38856    53.3 %   3499   174/256    4.8s   12.9s   0.47

 74 PlentyChess7.0.15-8t-MuPV4               : 3520    2  38666    52.9 %   3499   171/256    4.5s   13.0s   0.46

 84 Obsidian16.0-avx512-8t-MuPV4             : 3516    2  38141    52.3 %   3500   164/256    4.4s   13.6s   0.49

 99 Reckless0.8.0-8t                         : 3506    2  38008    50.8 %   3500   164/256    5.3s   14.2s   0.42

142 Dragon3.3-6t-MuPV4                       : 3468    2  36033    45.1 %   3502   138/256    6.5s   17.3s   0.34

159 Patricia5.0-6t-MuPV4                     : 3435    2  35655    40.4 %   3502   131/256    9.5s   19.5s   0.16
160 Monty-251201-8t-Co100                    : 3433    2  34486    40.1 %   3503   100/256    4.1s   19.9s   0.29
161 Patricia5.0extremeEAS-6t-MuPV4           : 3432    2  35521    40.0 %   3503   127/256    9.3s   19.7s   0.17

163 Arasan25.3-8t-MuPV4                      : 3429    2  34908    39.5 %   3502   110/256    7.1s   20.1s   0.24
164 Fritz20-6t-MuPV4                         : 3428    2  34255    39.3 %   3504   115/256    7.4s   19.8s   0.23

182 Dragon1-MCTS-6t-MuPV4                    : 3308    2  30667    24.1 %   3507    42/256    7.5s   26.3s   0.06

MST1  : Mean solution time (solved positions only)
MST2  : Mean solution time (solved and unsolved positions)
RIndex: Score according to solution time ranking for each position

Arasan 25.3 is at nr. 163 there. Latest SF and Reckless- versions missing in this one list, started a new one for the newest versions with new PC later on but wanted to compare Arasan with more engines and versions, so far already rated 182 runs, 3500 StatTS- Elo (Frank Schubert's- tool) set for average opponents' rating.

A little head to head- match with 3'+1" single thread (4.3GHz), UHO 2024 900-990cp 6mvs:

Score of Patricia5 vs Arasan25.3: 51 - 209 - 240 [0.342]
Elo difference: -113.7 +/- 21.9, LOS: 0.0 %, DrawRatio: 48.0 %
500 of 500 games finished.

[chessica]

Arasan 25.3 is available from https://arasanchess.org.

Thanks for the new version!
With the known 256 and 30"/position:

Code: Select all

    Program                                    Elo   +/-  Matches  Score   Av.Op.   S.Pos.   MST1    MST2   RIndex

  1 RemsM-091224-8t-26-4-2000                : 3583    2  42730    62.1 %   3497   218/256    3.3s    7.3s   0.66
  
 14 Stockfish17.1-8t-MuPV4-avx512            : 3550    2  40916    57.4 %   3498   195/256    4.3s   10.4s   0.56
 
 18 Lc0v0.32.0-rc2-1740-MuPV4                : 3546    2  39868    56.8 %   3499   193/256    4.8s   11.0s   0.57
 
 30 PlentyChess7.0.22-8t-MuPV4               : 3539    2  39564    55.8 %   3499   181/256    3.8s   11.4s   0.54

 37 Lc0v0.32.0-dev-1740-MuPV1                : 3538    2  39182    55.5 %   3500   180/256    4.0s   11.7s   0.56
 
 45 Stockfish-251014-8t-MuPV4                : 3534    2  39756    55.2 %   3499   183/256    4.6s   11.8s   0.52

 56 Stockfish-TI-251109-8t-MuPV4             : 3531    2  38911    54.6 %   3499   174/256    3.7s   12.2s   0.53

 70 Obsidian-16.15-8t-Co100-MuPV4            : 3522    2  38856    53.3 %   3499   174/256    4.8s   12.9s   0.47

 74 PlentyChess7.0.15-8t-MuPV4               : 3520    2  38666    52.9 %   3499   171/256    4.5s   13.0s   0.46

 84 Obsidian16.0-avx512-8t-MuPV4             : 3516    2  38141    52.3 %   3500   164/256    4.4s   13.6s   0.49

 99 Reckless0.8.0-8t                         : 3506    2  38008    50.8 %   3500   164/256    5.3s   14.2s   0.42

142 Dragon3.3-6t-MuPV4                       : 3468    2  36033    45.1 %   3502   138/256    6.5s   17.3s   0.34

159 Patricia5.0-6t-MuPV4                     : 3435    2  35655    40.4 %   3502   131/256    9.5s   19.5s   0.16
160 Monty-251201-8t-Co100                    : 3433    2  34486    40.1 %   3503   100/256    4.1s   19.9s   0.29
161 Patricia5.0extremeEAS-6t-MuPV4           : 3432    2  35521    40.0 %   3503   127/256    9.3s   19.7s   0.17

163 Arasan25.3-8t-MuPV4                      : 3429    2  34908    39.5 %   3502   110/256    7.1s   20.1s   0.24
164 Fritz20-6t-MuPV4                         : 3428    2  34255    39.3 %   3504   115/256    7.4s   19.8s   0.23

182 Dragon1-MCTS-6t-MuPV4                    : 3308    2  30667    24.1 %   3507    42/256    7.5s   26.3s   0.06

MST1  : Mean solution time (solved positions only)
MST2  : Mean solution time (solved and unsolved positions)
RIndex: Score according to solution time ranking for each position

Arasan 25.3 is at nr. 163 there. Latest SF and Reckless- versions missing in this one list, started a new one for the newest versions with new PC later on but wanted to compare Arasan with more engines and versions, so far already rated 182 runs, 3500 StatTS- Elo (Frank Schubert's- tool) set for average opponents' rating.

A little head to head- match with 3'+1" single thread (4.3GHz), UHO 2024 900-990cp 6mvs:

Score of Patricia5 vs Arasan25.3: 51 - 209 - 240 [0.342]
Elo difference: -113.7 +/- 21.9, LOS: 0.0 %, DrawRatio: 48.0 %
500 of 500 games finished.

What kind of engine is REMS? Is there a source for download?

[peter]

What kind of engine is REMS? Is there a source for download?

Not anymore, since Eduard Nemeth removed it form his site. The follow- up version with internal MultiPV is called Leptir.

https://solistachess.jimdosite.com/engines/

Here

viewtopic.php?p=986242#p986242

and here

viewtopic.php?p=986357#p986357

I had already both of them compared to each other with new PC, Arasan's run is in older one EloStatTS- list with more runs stored, especially such ones of lower numbers of solved positions.

[jdart]

I believe the BookPath option should include book.bin, i.e. it is a fully-specified filename. The default is to load the book from the same directory where the engine is, which seems to be the case here. So you could try just not specifying BookPath.

Arasan 25.3 is available from https://arasanchess.org.

Changes in Arasan 25.3:
1) Increase L1 size to 1792
2) New network, trained on 6B+ lc0 + selfplay games
3) Fix training script to sync with recent bullet updates
4) More changes to book selection logic
5) Omit positions from book with blunder eval or only losses
6) Code cleanup, especially in the SIMD code
7) Fix incorrect filtering of tablebase moves at root
8) Update to latest Fathom
9) Bug fixes involving handling of search statistics
10) Ponder option fixes. Set ponder off by default.
11) Fixes to CMakeLists.txt
12) import lichess-org/chess-openings for ECO coding

This has a significant, but not large, strength increase compared to the last release.

76828*1*----------------------Starte Motor 1 Arasanx-64-avx512----------------------
76828*1*Configured Engine 1 Type: UCI
76828*1*Engine 1 dir: C:\Program Files\arena_3.5.1\Engines\arasan25.3
76828*1*Engine 1 commandline: "C:\Program Files\arena_3.5.1\Engines\arasan25.3\arasanx-64-avx512.exe"
76938*1*Child Process Prio Adj: PID 11544 conhost.exe
76938*1*Engine 1 ProcessID: 7404
76953*1*Engine 1 Prio:32 ThreadPrio:0
76984 <first : Arasan 25.3 Copyright 1994-2025 by Jon Dart. All Rights Reserved.
76984 >first : uci
76984 <first : id name Arasan 25.3
76984 <first : id author Jon Dart
76984 <first : option name Hash type spin default 32 min 4 max 64000
76984 <first : option name Ponder type check default false
76984 <first : option name Contempt type spin default 0 min -200 max 200
76984 <first : option name Use tablebases type check default false
76984 <first : option name SyzygyPath type string default syzygy
76984 <first : option name SyzygyUse50MoveRule type check default true
76984 <first : option name SyzygyProbeDepth type spin default 4 min 0 max 64
76984 <first : option name MultiPV type spin default 1 min 1 max 10
76984 <first : option name OwnBook type check default true
76984 <first : option name BookPath type string default C:\Program Files\arena_3.5.1\Engines\arasan25.3\book.bin
76984 <first : option name Book variety type spin default 50 min 0 max 100
76984 <first : option name Threads type spin default 1 min 1 max 512
76984 <first : option name Position learning type check default false
76984 <first : option name Learning file type string default C:\Users\Privat\AppData\Roaming\Arasan\arasan.lrn
76984 <first : option name UCI_LimitStrength type check default false
76984 <first : option name UCI_Elo type spin default 3450 min 1000 max 3450
76984 <first : option name NNUE file type string default arasanv5-20251222.nnue
76984 <first : option name Move overhead type spin default 30 min 0 max 1000
76984 <first : uciok
76984 >first : setoption name Hash value 1024
76984 >first : setoption name BookPath value C:\Program Files\arena_3.5.1\Engines\arasan25.3
76984 >first : setoption name Learning file value C:\Users\Privat\AppData\Roaming\Arasan\arasan.lrn
77000*1*Child Process Prio Adj: PID 11544 conhost.exe
77000 >first : isready
77234 <first : loaded network from file C:\Program Files\arena_3.5.1\Engines\arasan25.3\arasanv5-20251222.nnue
77234 <first : info string warning: opening book not found or invalid
77234 <first : info string warning: opening book not found or invalid
77234 <first : readyok

[chessica]

Code: Select all

30578 >first : quit
30953*1*---------------------Starte Motor 1 Arasanx-25,3-avx512---------------------
30953*1*Configured Engine 1 Type:   UCI
30953*1*Engine 1 dir: C:\Program Files\arena_3.5.1\Engines\arasan25.3
30953*1*Engine 1 commandline: "C:\Program Files\arena_3.5.1\Engines\arasan25.3\arasanx-64-avx512.exe" 
31078*1*Child Process Prio Adj:  PID 8940 conhost.exe
31078*1*Engine 1 ProcessID: 11560
31078*1*Engine 1 Prio:32 ThreadPrio:0
31078 <first : Arasan 25.3 Copyright 1994-2025 by Jon Dart. All Rights Reserved.
31110 >first : uci
31110 <first : id name Arasan 25.3
31110 <first : id author Jon Dart
31110 <first : option name Hash type spin default 32 min 4 max 64000
31110 <first : option name Ponder type check default false
31110 <first : option name Contempt type spin default 0 min -200 max 200
31110 <first : option name Use tablebases type check default false
31110 <first : option name SyzygyPath type string default syzygy
31110 <first : option name SyzygyUse50MoveRule type check default true
31110 <first : option name SyzygyProbeDepth type spin default 4 min 0 max 64
31110 <first : option name MultiPV type spin default 1 min 1 max 10
31110 <first : option name OwnBook type check default true
31110 <first : option name BookPath type string default C:\Program Files\arena_3.5.1\Engines\arasan25.3\book.bin
31110 <first : option name Book variety type spin default 50 min 0 max 100
31110 <first : option name Threads type spin default 1 min 1 max 512
31110 <first : option name Position learning type check default false
31110 <first : option name Learning file type string default C:\Users\Privat\AppData\Roaming\Arasan\arasan.lrn
31110 <first : option name UCI_LimitStrength type check default false
31110 <first : option name UCI_Elo type spin default 3450 min 1000 max 3450
31110 <first : option name NNUE file type string default arasanv5-20251222.nnue
31110 <first : option name Move overhead type spin default 30 min 0 max 1000
31110 <first : uciok
31110 >first : setoption name Hash value 1024
31110 >first : setoption name BookPath value 
31110 >first : setoption name Learning file value C:\Users\Privat\AppData\Roaming\Arasan\arasan.lrn
31110*1*Child Process Prio Adj:  PID 8940 conhost.exe
31125 >first : isready
31344 <first : loaded network from file C:\Program Files\arena_3.5.1\Engines\arasan25.3\arasanv5-20251222.nnue
31344 <first : info string loaded opening book from file C:\Program Files\arena_3.5.1\Engines\arasan25.3\book.bin
31344 <first : readyok

However, the learning file should also be located in the engine directory and not here: C:\Users\Private\AppData\Roaming\Arasan\arasan.lrn

[jdart]

However, the learning file should also be located in the engine directory and not here: C:\Users\Private\AppData\Roaming\Arasan\arasan.lrn

That location is what is recommended for Windows apps. Arasan does not assume the installation directory is writable by the current user, but the directory you mention will be writeable. However, the default location of the learning file can be overridden via an option.