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Koivisto 9.0 - released.

The long-awaited ninth version of one of the most powerful chess engines just had a premiere. Koivisto is a free open source engine.

Source: GitHub

January 15, 20202. Here's what Koivisto Chess Engine Developers wrote:


Today, we are excited to announce the release of Koivisto 9. After a six-month break, we are back and eager to continue development. The majority of the strength increase since Koivisto 8 comes from improvements in training data, but we also made some small search adjustments.

ELO   | 89.70 +- 3.53 (95%)
CONF  | 8.0+0.08s Threads=1 Hash=8MB
GAMES | N: 20000 W: 7876 L: 2824 D: 9300

We had the pleasure of working with Jay (author of Berserk) which resulted in both of our engines merging and sharing a neural network training framework as well as training data. This collaboration led to a significant increase in strength:

ELO   | 19.41 +- 6.65 (95%)
SPRT  | 40.0+0.40s Threads=1 Hash=64MB
LLR   | 2.95 (-2.94, 2.94) [0.00, 2.50]
GAMES | N: 5072 W: 1369 L: 1086 D: 2617

ELO   | 20.02 +- 6.80 (95%)
SPRT  | 8.0+0.08s Threads=1 Hash=8MB
LLR   | 2.96 (-2.94, 2.94) [0.00, 2.50]
GAMES | N: 4968 W: 1373 L: 1087 D: 2508

The addition of more training data also contributed to nice gains:

ELO   | 29.79 +- 2.91 (95%)
CONF  | 8.0+0.08s Threads=1 Hash=8MB
GAMES | N: 16848 W: 3334 L: 1893 D: 11621

Although we don't have regression tests to show for the search improvements and speed-ups, they are where the rest of the gains come from. Attached you can find executables for AVX2 and SSE systems. Executables for PEXT and/or AVX512 systems are available via Ipman. With love and appreciation, Finny and Kimmy.


Source: GitHub

I am very happy to see the cooperation of Koivisto Creators together with Jay Honnold Creator of Berserk. Koivisto and Berserk are some of the most powerful open source chess engines on planet earth!

I'm very curious to see how the latest Koivisto will do in MCERL; results coming in the next few days :)

Download Koivisto 9.0

As of the publication date of this post, you can download the Koivisto 9.0 chess engine in x64 versions for Linux and Windows from the project's website.


Feel free to directly download Koivisto 9.0 from here:

Android – Compiled by Archimedes

Download 7Z • 58.60MB

Linux arm64 & x64 – Compiled by Darius

Download 7Z • 50.75MB
Download 7Z • 53.17MB

Mac Apple Silicon & Intel – Compiled by Darius

Download 7Z • 50.83MB
Download 7Z • 50.95MB

Windows x86_64 – Compiled by Darius

Download 7Z • 52.18MB


For your convenience, in the Files area you will find all chess engines for download, which I post in the News section.



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