Koivisto v4.0 release

[EugenioBruno]

Koivisto v4.0

A while ago, we released Koivisto v3.0 after a significant improvement in strength. It's time for another release again

We'd like to thank Andrew Grant for the OpenBench framework (and putting up with our questions about it!), without which we wouldn't be able to test so many new ideas; it has greatly improved our experimentation process since we started using it around Koivisto v2.0.
We'd also like to thank noobpwnftw for significant help with testing.

Our latest regression test shows significant Elo gain over Koivisto v3.0:

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60+0.6:
ELO   | 141.20 +- 18.81 (95%)
SPRT  | 60.0+0.6s Threads=1 Hash=64MB
LLR   | 0.00 (-2.94, 2.94) [0.00, 0.00]
Games | N: 960 W: 501 L: 131 D: 328

15+0.1:
ELO   | 120.88 +- 13.38 (95%)
SPRT  | 15.0+0.15s Threads=1 Hash=16MB
LLR   | 0.00 (-2.94, 2.94) [0.00, 0.00]
Games | N: 1952 W: 1002 L: 349 D: 601

Furthermore, from cyclic time controls, one can expect significantly higher performance than before. Testing by CCRL members made issues apparent in how we handled cyclic time controls. This test shows the same version of the engine, but using the new cyclic time control manager.

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40/15:
ELO   | 84.12 +- 20.83 (95%)
SPRT  | 40/15s Threads=1 Hash=16MB
LLR   | 3.11 (-2.94, 2.94) [0.00, 5.00]
Games | N: 640 W: 260 L: 108 D: 272

We are always thankful for community testing. In particular we're anxious to see whether our SMP scales as well as we hope

Changes:

- updated tt-usage.
- does forced moves immediately.
- added bishop pawn endgame relations evaluation term.
- retuned entire evaluation with a larger dataset.
-> tuned mobility scores instead of computing them.
-> tuned king safety scores instead of computing them.
- cleaned up the code and added comments.
- asymmetric piece square tables based on king-king relation.
- changed reduction/extension policy.
- improved general time management.
- fixed cyclic time management which leads to the engine using a lot more time in games with cyclic time controls.
- fixed speed-related issues.
- added a logo and banner.

The Koivisto engine authors, Kim, Finn and Eugenio.

[bastiball]

It won't start, it says "The procedure entry point pthrerad_getaffinity_np could not be located in the dynamic library *files path to the engine"

[Koivisto]

It won't start, it says "The procedure entry point pthrerad_getaffinity_np could not be located in the dynamic library *files path to the engine"

Seems like the windows binaries are dynamically linked. I don't have access to a windows machine so I notified Finn and Eugenio.

[bastiball]

Forgot to tell that I use Window Binaries and I'll wait for the update, thanks a lot.

[Luecx]

Forgot to tell that I use Window Binaries and I'll wait for the update, thanks a lot.

Okay so I had a quick look and you are right, the compiles dont seem to work properly.
If you are able to compile, try compiling it yourself using:

Code: Select all

make native

which should produce multiple statically compiled binaries.

I reuploaded the static compiles. Hopefully it will work now

[bastiball]

It's working now. Thanks

[Gabor Szots]

Hi Eugenio,

I'm going to test it as soon as I have a chance but my Koivisto 3.0 test is still running. You know, that 'a while ago' was in fact only 3 weeks ago...

[Sylwy]

My test started:

[EugenioBruno]

Hi Eugenio,

I'm going to test it as soon as I have a chance but my Koivisto 3.0 test is still running. You know, that 'a while ago' was in fact only 3 weeks ago...

Haha, indeed! Thanks you for the testing - I believe it was actually some of your games that showed us issues with our time management.

I (unfortunately) don't think we'll be able to extrapolate this release frequency in the future. We've had a very, very rough guideline of making a new major release if we get +100 vs the previous version, and since the regression test was +140, we decided to release - with apologies and thanks to all the testers for the headaches caused!

[Sylwy]

....if we get +100 vs the previous version, and since the regression test was +140, we decided to release - with apologies and thanks to all the testers for the headaches caused!

After 60 games in my test (TC=4'+2"-around 12-15 minutes per game) Koivisto 4.0 shows near +40 Elo points over Koivisto 3.0. Let's see what will be in the end.