New engine releases & news H1 2026

[NathanDrake]

My understanding is that it uses SF nets.

Hi Graham, that's correctt. It uses Stockfish's HalfKAv2_hm network (nn-b1a57edbea57.nnue) and the NNUE inference code from SF.

The release also includes an in-house net (nn-rubicon-v1.nnue), selectable via UCI option. Though it currently runs about 60 Elo below the SF default net.

[Graham Banks]

My understanding is that it uses SF nets.

Hi Graham, that's correctt. It uses Stockfish's HalfKAv2_hm network (nn-b1a57edbea57.nnue) and the NNUE inference code from SF.

The release also includes an in-house net (nn-rubicon-v1.nnue), selectable via UCI option. Though it currently runs about 60 Elo below the SF default net.

So is the rubicon net one that you trained yourself?
What games did you use?
Sorry for all the questions.

[NathanDrake]

My understanding is that it uses SF nets.

Hi Graham, that's correctt. It uses Stockfish's HalfKAv2_hm network (nn-b1a57edbea57.nnue) and the NNUE inference code from SF.

The release also includes an in-house net (nn-rubicon-v1.nnue), selectable via UCI option. Though it currently runs about 60 Elo below the SF default net.

So is the rubicon net one that you trained yourself?
What games did you use?
Sorry for all the questions.

Yes, i trained it myself using T80 datasets and google cloud GPU for computing power.
No problems for the questions!

[Sylwy]

In repo version 4.0 (.exe-avx2) is in fact 3.9 ???

[NathanDrake]

In repo version 4.0 (.exe-avx2) is in fact 3.9 ???

No, it shouln't, why?
EDIT: i checked, it's just an error in the presentation screen. The version is actually the correct 4.0, I'll update as soon as possible. You can use it.

[Sylwy]

Some infos - v4.0:

-Intel i5-7400 (Kaby Lake);
-Windows 10 x64 - AVX2 build;
-both NNUEs present;
-v3.3 works;
-4.0 crashes after 2-3 seconds (in console mode);
-Arena 3.5.1 GUI shows Hash=0 (in engine window).

[Andres Valverde]

EveAnn 5.1 released

https://sites.google.com/view/dirtychess/dirtychess

New NN , HCE fixed. Estimated +15/20 ELO at long TC

[NathanDrake]

Some infos - v4.0:

-Intel i5-7400 (Kaby Lake);
-Windows 10 x64 - AVX2 build;
-both NNUEs present;
-v3.3 works;
-4.0 crashes after 2-3 seconds (in console mode);
-Arena 3.5.1 GUI shows Hash=0 (in engine window).

I just fixed the release number and recompiled. I am updating the release now.

[NathanDrake]

Some infos - v4.0:

-Intel i5-7400 (Kaby Lake);
-Windows 10 x64 - AVX2 build;
-both NNUEs present;
-v3.3 works;
-4.0 crashes after 2-3 seconds (in console mode);
-Arena 3.5.1 GUI shows Hash=0 (in engine window).

The _avx2 binary of the 4.0 release accidentally contains a handful of AVX-512
instructions in the NNUE evaluation path (a build-script flaw on my side). On
CPUs without AVX-512 (your Kaby Lake, and anything pre-Ice Lake / pre-Zen4)
the engine starts, answers UCI, and dies with an illegal instruction on the
first evaluation, which matches your "crashes after 2-3 seconds" and Arena
showing Hash=0 exactly.

A fixed _avx2 binary (verified clean of AVX-512 this time, with an automated
check added to the build pipeline) is being rebuilt right now and I will
replace the release asset shortly.

[Sylwy]

Some infos - v4.0:

-Intel i5-7400 (Kaby Lake);
-Windows 10 x64 - AVX2 build;
-both NNUEs present;
-v3.3 works;
-4.0 crashes after 2-3 seconds (in console mode);
-Arena 3.5.1 GUI shows Hash=0 (in engine window).

The _avx2 binary of the 4.0 release accidentally contains a handful of AVX-512
instructions in the NNUE evaluation path (a build-script flaw on my side). On
CPUs without AVX-512 (your Kaby Lake, and anything pre-Ice Lake / pre-Zen4)
the engine starts, answers UCI, and dies with an illegal instruction on the
first evaluation, which matches your "crashes after 2-3 seconds" and Arena
showing Hash=0 exactly.

A fixed _avx2 binary (verified clean of AVX-512 this time, with an automated
check added to the build pipeline) is being rebuilt right now and I will
replace the release asset shortly.

Funziona perfettamente! Grazie mille!!!

Compilavi. Testavi. Victoriam reportavi!