Wednesday, October 14, 2015

Nirvanachess 2.2 Release

What is new in this release?

  •  Tuning with Texel's tuning method
    • Improved mobility evaluation
    • Improved Passed Pawns evaluation
    • Improved Shelter and Storming pawns evaluation
  •  SPSA tuning
    • Tuned LMP
    • Tuned LMR
  • Speed ups
    • Improved move generation speed by approximately 10%
  • New Features
    • Now accepts the "movetime" command
    • Now able to handle more than 16 gb of hash
  • Bug Fixes
    • Fixed a crash that could have occurred during late game ends
    • Fixed a crash with SMP
    • Fixed node counting during SMP
    • SMP now scales well beyond 4 cores.
 Overall strength gain ~50 elo after 5000 games against 2.1c at 60"+0.05"



  1. Better three hours too soon than a minute too late. See the link below for more info.


  2. I really enjoyed reading your article. I found this as an informative and interesting post, so i think it is very useful and knowledgeable. I would like to thank you for the effort you have made in writing this article.

  3. The Nirvana version 2.2 32-bit release returns the error message "Not a valid win32 application". Yet the binary file also refers to not running in ms-dos mode.-??? Please advise.

  4. The engines run only on my 64-bit machine under Windows 7, but do not appear to be fully UCI compliant. Typing uci after load returned nothing....

  5. Hello!
    The Nirvana 2.2 (32-bit) does not work under Windows XP (SP3).
    I've installed all the sugested Microsoft files.
    The Arena GUI displays the folowing message:
    "Error: Could not start the engine."
    Please help me.
    Thank you.

  6. 2.2 popcount works fine for me running Win 10 with Arena 3.5.1.