Zevra chess engine - I went back to development

[sovaz1997]

Good result!
Thanks for testing!!!

[sovaz1997]

Hey! Today I am releasing a new version of Zevra: Zevra v2.5!
This version has a big improvement in game level - about 80 elo points.

This version includes the following changes:

• Fix big in the calculation of the piece weights in the params tuner (tuning uses a specific calculation of the eval for speed-up);
• Add tapered eval for mobility;
• Restarting the tuner from scratch for a qualitative improvement in the eval. It seems to me that the ideal iterations count in Texel's tuning is about 50-80 iterations for ~900 params and 1 000 000 positions. If more or less, it will be a Elo loss;
• The hash is now 2-bucket. This gave a slight improvement in game level, but Zevra now solve positions faster.

Test results:

Code: Select all

tc=10+0.1
Games: 3000/3000 W: 1337 L: 658 D: 1005
ELO: 80.02 +- 10.25 (95%) LOS: 100.00%

Code: Select all

tc=60+0.6
Games: 1000/1000 W: 430 L: 211 D: 359
ELO: 77.34 +- 17.41 (95%) LOS: 100.00%

https://github.com/sovaz1997/Zevra2/releases

[Rebel]

Running Zevra 2.5 for the GRL.

Games : 1000

Elo pool : 2662

http://rebel13.nl/a/grl.htm

[sovaz1997]

Running Zevra 2.5 for the GRL.

Games : 1000

Elo pool : 2662

http://rebel13.nl/a/grl.htm

Thanks for testing!

[Rebel]

Zevra 2.5 +45

Details at - https://prodeo.actieforum.com/t358p25-g ... sults#4614

[sovaz1997]

Zevra 2.5 +45

Details at - https://prodeo.actieforum.com/t358p25-g ... sults#4614

Good result
Like in my tests, perhaps Zevra v2.4 showed an overestimated performance (in any case, according to my tests, it is slightly lower):

Code: Select all

   # PLAYER                      :  RATING  ERROR  POINTS  PLAYED   (%)
   1 Komodo 7a 64-bit            :  3318.8   39.3  3506.5    3551    99
   2 WyldChess                   :  2673.6   19.3  1036.5    1794    58
   3 Zevra v2.5                  :  2656.1   16.0  2344.5    3978    59
   4 Zevra v2.4 r380             :  2581.7   18.4   861.0    1808    48
   5 Zevra v2.3 r348             :  2542.4   18.4   768.5    1795    43
   6 Galjoen 0.41.2              :  2503.1   18.3   684.0    1793    38
   7 CT800 V1.43 64 bit          :  2492.6   18.4   664.5    1798    37
   8 Zevra v2.2.1 r328           :  2436.1   18.3   542.0    1786    30
   9 Loki 3.5.0                  :  2421.6   18.7   517.0    1795    29
  10 Zevra v2.1.2 r248           :  2419.0   ----   510.5    1789    29
  11 Teki 2                      :  2362.2   19.2   405.0    1793    23