Arasan 24.1

[jdart]

Arasan 24.1 is available from https://www.arasanchess.org.

Changes in Arasan 24.1:
1) Fix scoring for special case endgames (classical eval).
2) Add HCE scoring for KRN vs KR and KRB vs KR.
3) Fixes/tuning for strength reduction feature.
4) Add option to override opening book path.
5) Multiple fixes and updates to selfplay utility.
6) Updated network, trained on approx. 4.7B self-play games.
7) SIMD optimizations in NNUE feature transformer (significant
performance increase, especially for Mac M1/M2 and AVX512).
8) Bug fixes in NNUE code.

[Frank Quisinsky]

Hi Jon,

at first, have a good start in the new year 2024.
at second, thanks for your new version!
...

at third
In your v24.1 download on your website:
https://www.arasanchess.org/index.shtml

the NN file missed!

On your github:
https://github.com/jdart1/arasan-chess

I found:
arasan-d9-SFv4-20231228.nnue

Should we used this NN file for Arasan 24.1?
Or the older one from version 24.0 or maybe you forgot your last one for 24.1?

Best
Frank

[jdart]

In your v24.1 download on your website:
https://www.arasanchess.org/index.shtml

the NN file missed!

Sorry about that - I updated the .zip file. The latest network file is arasan-d9-SFv4-20231228.nnue.

[Frank Quisinsky]

Thanks!

Best
Frank

[Graham Banks]

In your v24.1 download on your website:
https://www.arasanchess.org/index.shtml

the NN file missed!

Sorry about that - I updated the .zip file. The latest network file is arasan-d9-SFv4-20231228.nnue.

The file I downloaded earlier was 14.1mb, so I thought it included the net.

[jdart]

1600 games @ 2:0+1 shows a modest gain over 24.0 (Linux, avx2 build):
Score of Arasan-Test vs Arasan-Base: 197 - 108 - 1295 [0.528] 1600
Elo difference: 19.35 +/- 7.39

[peter]

Thanks for the new version, Jon!
Position- learning still doesn't work in UCI nor in WinBoard, does it?
It does in xboard- mode (e.g. cutechess), regards

[jdart]

Thanks for the new version, Jon!
Position- learning still doesn't work in UCI nor in WinBoard, does it?
It does in xboard- mode (e.g. cutechess), regards

It does not work under UCI - that is still a to-do item. It should work under Winboard if you are using the engine in CECP mode (the default).

[Dariusz]

Arasan 24.1 is available from https://www.arasanchess.org.

Changes in Arasan 24.1:
(...)
7) SIMD optimizations in NNUE feature transformer (significant
performance increase, especially for Mac M1/M2 and AVX512).
8) Bug fixes in NNUE code.

Jon, indeed, I can see after the first few hundred games (MCERL) that the increase in strength of Arasan 24.1 neon is significant. On my mac M1 , at this point oscillates around +120 elo than previous version!

Hearty congratulations and thank you for this excellent Arasan

[Frank Quisinsky]

Hi Jon,

I have no idea what is wrong with Arasan 24.1 or my configuration.

When I compare NPS, Arasan 24.1 is a bit faster than Arasan 24.0 ... first look ... all is OK.
But when I compare the depth ... the depth is clearly higher from Arasan 24.0. Depth 21 (v24.1) to depth 24-25 (v24.0) after 5-6 seconds.

Simply test:
1. h2-h3 and compare the depth between the two versions.

I do this because after about 75 games the performance in my blitz tournament against new releases is 33%. But I expect much more than 60%. Something is wrong and I can't find any error in my configuration.

Best regards
Frank

What do you need?
A debug file?
Maybe you can compare it yourself with your older version 24.0!

Have tried: AVX2-BMI2, AVX2 and Modern on Intel i9-10900k (Windows 10) and i7-1185g7 (Windows 11)