Releases

Ceibo 0.9 - August 08, 2022

Changes:

  • Search

    • Tuned Futility Pruning

    • Tuned Null Move Pruning

    • Tuned History Heuristics

    • Added Aspiration Window

    • Added Syzygy Tablebase support

    • Added Dynamic Time Management

    • Reworked multithreading

  • Move generator

    • Modified into staged move generator

    • Various Minor speed improvements on the generator and make/undo

    • Improved validations to prevent illegal moves

  • Eval terms

    • Scaling based on rule 50

    • Reworked mobility eval

    • Added tempo eval term

    • Knight/Bishop outpost

    • Knight/Bishop behind pawn

    • Blocked Pawns on bishop color

    • Rook/Queen infiltration

  • Misc

    • Added upper/lowerbound info strings

    • Various other smaller changes.


Compare Ceibo releases in CCRL 40/15

Compare Ceibo releases in CCRL Blitz

  • Ceibo 0.8 - August 29, 2021

Changes:

  • Move Ordering

      • Static Exchange Evaluation (SEE): applied to captures only for now.

      • Other minor changes

    • Search

      • Qsearch: SEE Pruning

      • Internal Iterative Reductions

      • Fixed Futility Pruning issue

    • Transposition Tables

      • Fixed Major move ordering issue

      • Fixed Minor en passant issue

      • 4 buckets per entry

  • Evaluation:

    • semi and open file rook

    • isolated pawn

    • enhancements to mobility


Ceibo 0.8 - CCRL 40/15

Ceibo 0.8 - CCRL Blitz


  • Ceibo 0.7 - June 24, 2021

Changes:

  • Board Representation: Bitboards! (old school; no rotated/no magic)

  • Movegen: completely reworked from scratch

  • Evaluation:

    • added king safety (my engine actually tries to protect the king ! how about that? )

    • added safe mobility

    • added more pawn structure terms

    • texel tuned

  • Null Move: tuned parameters, removed useless conditions and added new criteria

  • LMR: tuned for longer Time Controls

  • fixed issue where moves to mate where incorrectly reported

  • removed bugs and added new ones

  • + many minor changes, enhancements, code clean up, etc


Ceibo 0.7 64-bit in CCRL 40/15 : ELO 2611 +/- 70 (preliminary)

Ceibo 0.7 64-bit in CCRL Blitz : ELO 2601 +/- 25



  • Ceibo 0.6 - Feb 12, 2021

Changes:

  • Late Move Reduction

  • SMP *

  • minor enhancements and code clean up

* Up to 4 threads. Unfortunately I only have a 4 core CPU and therefore could not not test beyond that. However, I have not enforced a max thread count and should work with higher concurrency just as well.


Ceibo 0.6 64-bit in CCRL 40/15 : ELO 2378

Ceibo 0.6 64-bit in CCRL Blitz : ELO 2390


  • Ceibo 0.5 - Jun 19, 2020

Ceibo 0.5 64-bit in CCRL 40/15: ELO 2351

Ceibo 0.5 64-bit in CCRL Blitz : ELO 2325


  • Ceibo 0.4 - Mar 21, 2018

Ceibo 0.4 64-bit in CCRL 40/15 : ELO 2021

Ceibo 0.4 64-bit in CCRL Blitz : ELO 1994


  • Ceibo 0.3.65 - Dec 11, 2017

Ceibo 0.6.65 64-bit in CCRL Blitz : ELO 1721