Marvin 5.0.0

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Posts: 33
Joined: Sun Jul 10, 2016 7:12 pm
Location: Lund, Sweden
Full name: Martin Danielsson

Marvin 5.0.0

Post by Martin » Tue Jan 12, 2021 5:45 pm

Marvin 5.0.0 is now available. The big change in this release is the switch to NNUE based evaluation. In my tests it is about 60 elo stronger compared to the previous version. A default network file is included in the binary package. Just put the file in the same directory as the executable and it should be detected and used automatically.

For network inference I have written my own code. It doesn't use any intrinsics, instead it relies on OpenMP and auto-vectorization. So the code is easy to understand but quite a lot slower than Stockfish/Cfish. To compensate for this I use smaller network, HalfKP 128x2-32-32 (network file is about 10MB).

Data for training was generated by Marvin 4.0.0 self-play. The default network was trained using 500M positions searched to depth 10. Code for the trainer is available here, It is based on the nnue-pytorch project and uses a lot of code from that project.

Binaries: ... tag/v5.0.0

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Graham Banks
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Location: Auckland, NZ

Re: Marvin 5.0.0

Post by Graham Banks » Tue Jan 12, 2021 9:23 pm

Nice. :)

I'll put it in the new tourney.
gbanksnz at

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Joined: Sat Oct 31, 2020 12:04 am
Full name: Aleksey Glebov

Re: Marvin 5.0.0

Post by Angle » Tue Jan 12, 2021 11:04 pm

Hi, Martin!
Great news! The shame is that I have just started a new tournament including 4.0.0 and 4.0.1 versions. But I think it is not late to replace one of the participants by Marvin 5.0.0 :P
Incredibly fast systems miscount incredibly fast.

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Re: Marvin 5.0.0

Post by jshriver » Wed Jan 13, 2021 5:09 am

Very cool, I look forward to playing it. :D

Gabor Szots
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Re: Marvin 5.0.0

Post by Gabor Szots » Wed Jan 13, 2021 7:50 am

Graham Banks wrote:
Tue Jan 12, 2021 9:23 pm
Nice. :)

I'll put it in the new tourney.
And I in my next gauntlet.
Gabor Szots
CCRL testing group

Frank Quisinsky
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Full name: Frank Quisinsky

Re: Marvin 5.0.0

Post by Frank Quisinsky » Wed Jan 13, 2021 9:24 am


after problem with an other engine I must make different changes for the still running FCP Tourney-2021.

A good chance to replaced Marvin 4.0.1 POPCNT x64 with Marvin 5.0.0 NN AVX2 x64.

Thank you!

I like computer chess!

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Re: Marvin 5.0.0

Post by Sylwy » Thu Jan 14, 2021 8:21 pm

Marvin 5.0.0 x64-avx2 plays well (& nice) in the match vs. Fritz 16 x64. The situation - in my 100 games test (TC=4'+2") - after 20 games:


Fritz 16 x64 has 3140 Elo points (CCRL Blitz rating list).

Here is the first victory of Marvin 5.0.0 x64-avx2:

SilvianR :wink:

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