Arasan 25.1

[jdart]

Arasan 25.1 is available from https://www.arasanchess.org.

Changes in Arasan 25.1:
1) Fixes for time management in zero-increment games
2) Changes to null move reduction formula
3) New network with L1=1536
4) Move NNUE code into the main source tree
5) Use pure NNUE eval, no more HCE
6) Changes to book selection logic
7) Updates to selfplay utility
8) Update match tools to use fastchess instead of cutechess-cli
9) increase MaxCPUs to 512 (for TCEC)

Testing against 25.0 at 1:0+0.8 time control:
2512 games, score: 53.74%
ELO: 26.05 +-5.8 (95%)
LOS: 100.0%

[Graham Banks]

Thanks, Jon.

[JohnW]

Thank you for the update. When I install it in Arena, I am getting a "error:invalid option name "Learning file name" error.
Is there something I need to do to configure it? The configuration seems very similar to Arena 24 where I don't get that error.
Thank you for your help.

[jdart]

When I install it in Arena, I am getting a "error:invalid option name "Learning file name" error.

The options have not changed since the last release. This looks like an Arena bug to me: possibly it objects to an option that has "name" in its name field.

[F.Huber]

When I install it in Arena, I am getting a "error:invalid option name "Learning file name" error.

The options have not changed since the last release. This looks like an Arena bug to me: possibly it objects to an option that has "name" in its name field.

No, the problem is in the engine: it sends the option "Learning file name" to the GUI, but it checks for "Learn file name" in the options returned from the GUI.

BTW, there's even a 2nd error message: invalid option name "Position learning".
This problem must have a different reason, I've not found any name conflicts for this option in the engine (as with the other error).
Edit: Maybe the problem here is the word 'Position', because 'position' is also a UCI command!?
Edit2: I've now changed "Learning file name" to "Learn file name" and "Position learning" to "Position_learning" in the engine, and both error messages have gone.

[Graham Banks]

Works fine in ChessGUI.

[F.Huber]

Works fine in ChessGUI.

Well, I guess ChessGUI just doesn't display such error messages, so you simply don't realize these 2 problems.

[Modern Times]

No errors displayed in CuteChess GUI either, but as you say it doesn't mean that they aren't there.

[F.Huber]

No errors displayed in CuteChess GUI either, but as you say it doesn't mean that they aren't there.

You can see such error messages (sent from the Arasan engine to the GUI), if the GUI is able to display the communication between GUI and engine - Arena has this possibility called 'Debug Window' (with F4).

[jdart]

No, the problem is in the engine: it sends the option "Learning file name" to the GUI, but it checks for "Learn file name" in the options returned from the GUI.

BTW, there's even a 2nd error message: invalid option name "Position learning".
This problem must have a different reason, I've not found any name conflicts for this option in the engine (as with the other error).
Edit: Maybe the problem here is the word 'Position', because 'position' is also a UCI command!?
Edit2: I've now changed "Learning file name" to "Learn file name" and "Position learning" to "Position_learning" in the engine, and both error messages have gone.

I will fix the first problem. Regarding the second, I don't think it should be necessary to change the name, in a properly functioning GUI.