Changes in version 0.83 compared to 0.80
109 files changed, 7623 insertions(+), 5955 deletions(-).
Changes that affect strength
Implement Late move reductions (LMR) (actually, re-implemented)
Revamp hash table system and remove specialized refutation table
Modify parallel search
Futility pruning parameters tuned
Extended futility pruning implemented
Nullmove adjusted according to depth and score (Dann Corbit’s snippet)
Style & Cosmetics
Modify pouncing mode. In TB draws, it will try to win using random evaluation scores
Remove option TB_pieces_installed. When probing, the engine will automatically recognize how many table bases are installed
Modify Zobrist keys (hardwired in the code from true random numbers from random.org)
Old books CANNOT be read for that reason. The internal format has changed.
Allow log "off" and ponder "on" at the same time (bug reported by Carlos Pesce)
Fix UCI output to properly report checkmates (reported by Marc Halstern)
Change node counters from 32 to 64 bits (overflow after 1 hour reported by Ray Banks)
Fix two potential (dormant) synchronization bugs (found with the debug version)
Fix bug to allow output of checkmates longer than 100 moves (reported by James I.)
Fix synchronization bug that happens when the opponent sends a quick response and does not allow a proper update of the internal data structures (reported by Leo Dijksman)
Fix bug that caused a loss of time in rare events. When there is ponder hit in the last move of the time control session, the engine thought there is more time available (reported by Leo Dijksman)
Fix endgame table base probing bug (reported by J. Merlino). In certain situations, en-passant square was not recognized properly
Fix endgame table base probing bug (reported by J. Merlino & O. Deville). Probing soft in the first two plies caused the engine to miss some TB moves.
Modify source code to remove an Intel Linux compiler bug when PGO is used. That solves problems in reading books in Linux 32 bits (also reported by J. Shriver).
Killer locks were not destroyed at the right place. Bug reported by Dann Corbit.
Modify source code to silence compiler warnings in GCC
Last edited by Victor on Wed Apr 27, 2011 11:48 am; edited 1 time in total