Nirvanachess 2.5 Release

 What is new in this release?

•  Evaluation tweaks
• Added some early game knowledge for queen threats.
• Search tweaks
• Extended LMR to killer moves too
  
• Speed ups
• Lots of general speed from more efficient code
• Optimized some LMR and Razoring values
• Bug Fixes
• Fixed a bug in some endgame bit bases
• Fixed a bug where PV would sometimes say there is a MATe when running out of time.
  
• UCI Parameters
• Added multiPV
  

Overall strength gain ~50 elo after 3000 games against 2.4 at 60"+0.05"

Download:
https://www.mediafire.com/file/u5xygnl28suxomn/Nirvanachess_2.5.rar/file

Nirvanachess 2.4 Release

What is new in this release?

•  Evaluation tweaks
• Improved King Safety evaluation
• More accurate values obtained from Hash
• Speed ups
• Use of template functions to improve speed
• SEE bug fix to reduce overhead 
• More aggressive LMR and LMP
• Endgame knowledge
•  Better evaluation during low pawn endings
• Bug Fixes
• Fix Pawn hash utilization bug
• Fix IID bug that caused failure to find moves under certain circumstances
• Fix bug during singular extension search

Overall strength gain ~45 elo after 3000 games against 2.3 at 60"+0.05"

Download:
http://www.mediafire.com/file/dqom3pbb9f9h796/Nirvanachess_2.4.rar

Nirvanachess 2.3 Release

What is new in this release?

•  Evaluation tweaks
• Improved mobility evaluation
• Improved Passed Pawns evaluation
• Improved Isolated Pawn values
•  Pieces that cannot move to the opponents side of the board are penalized
• Bishops scale off the number of blocked pawns
• Rooks scale based off the number of pawns
• Pieces without safe squares to move to are considered trapped
• Speed ups
• Added small hash for king safety
• Added dedicated thread for UCI input
• Endgame knowledge
• Added some fortress detection
• Added KPK bitbase
• Added draw knowledge for KRPKRP
• Bug Fixes
•  Fixed multiple rare crashes under SMP

Overall strength gain ~30 elo after 2000 games against 2.2 at 60"+0.05"

Download:
http://www.mediafire.com/download/ldc3e25vfcryydd/Nirvanachess_2.3.rar

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"

Download:
http://www.mediafire.com/download/hc0g330h79urej0/Nirvanachess+2.2.rar

Nirvanachess 2.1 Release

What is new in this release?

•  Tuning with Texel's tuning method
• Improved king safety evaluation
• Improved threats evaluation
• Improved mobility evaluation
•  SPSA tuning
• Further tuned pruning margins
• Added singular extensions
• Worth approximately 20 elo!
• Bug Fixes
• Fixed an SMP bug that would cause crashes when running more than one thread
• Fixed another SMP bug that caused threads to not start properly

 Overall strength gain ~80 elo after 5000 games against 2.0a at 60"+0.05"

Download:
http://www.mediafire.com/download/8hslhtv0h42phbj/Nirvanachess_2.1c.rar

Nirvanachess 2.0

What is new in this release?

• A complete rewrite of the engine
• Now uses bitboards instead of a 10x12 board representation 
• Improves the speed of the evaluation function
• Fixed multiple bugged located in the old evaluation function's code
• In particular backward pawns were completely incorrectly calculated
• Improved King safety
• Now considers safe checks against the king when calculating attacks
• Piece threats
• Hanging pieces are now penalized
• Now supports multiple cores.
• Lazy implementation threads only communicate via the hash table.
• Approximately 100 elo stronger than version 1.8 on a single core.

Download Link:
http://www.mediafire.com/download/5004wcpixd03f5d/Nirvanachess_2.0.rar

Nirvanachess 1.8 Release

What is new in this release?

• Strength Increase
• Scores 55% against Nirvanachess 1.7!
• Evaluation Tweaks
• Blocked passed pawns with a friendly blocker are now not penalized as much
• The Bishop pair is now based more than just the number of remaining pawns
• Includes enemy major and minor pieces
• Reverted Rook and Queen outposts
• Testing proved this to be a regression against other opponents
• Implemented a lazy evaluation based on material.
• Implemented Pawn hashing as well as pawn shelter hashing.
•  Search Tweaks
• Reverted LMP for bad captures
• Testing showed poor results at long time controls.
• Transposition Table Tweaks
•  Pv is no longer collected from the transposition table.
• Hashing now uses a cluster of four entries like in Fruit and Stockfish
• Hashing no longer uses an always replace scheme
• Older entries, Lower depth entries and non-pv entries are given lower prority
• Performs much better under high hash pressure
•  Bug Fixes
• Fixed a bug where under certain conditions killer moves would not be updated properly
• Standardized pruning at root and interior nodes
• Fixed a bug that caused all moves to be generated under certain conditions in Qsearch

Download Link:
http://www.mediafire.com/download/6b9i7eq657o6o2o/Nirvanachess_1.8.rar