v5.1 (Megumin), 07.06.2021

• Fixed Shredder and Fritz issues

v5.0 (Megumin), 12.04.2021

• Added more detailed evaluation info in pawn hash table entry
• Added futility pruning to quiescence search
• Added reuse of killer table between moves
• Added razoring
• Added ability to stop the search if reliable mate score was found
• Added search cut when enemy king is checked
• Added detection of the open file next to the king in the evaluation
• Added history heuristic veto in LMR
• Added late move pruning
• Fixed insufficient material detection when both sides had knight or bishop
• Fixed threefold repetition detection
• Fixed invalid depth in killer heuristic
• Fixed memory usage issues during the search
• Adjusted search parameters
• Adjusted evaluation parameters
• Allowed to use history heuristic values from the previous iterations
• Allowed late move reduction when capture has a negative score
• Improved time management when incrementation is present
• Improved Fianchetto detection
• Improved history table structure
• Enabled support for BMI instruction set (only if CPU supports it)
• Disabled futility pruning when enemy king is checked

v4.0 (Komekko), 22.01.2021

• Added Texel project
• Added check extension
• Added check detection in quiescence search
• Added evasion moves generator
• Added static null-move pruning
• Added futility pruning
• Added new formulas calculating reduction for LMR and null move pruning
• Added a new way of building Piece-Square tables, better for tuning
• Fixed redundant saving of transposition table entries
• Adjusted search parameters
• Adjusted evaluation parameters
• Improved threefold repetition detection
• Updated .NET runtime version to 5.0.102

v3.0 (Luna), 12.12.2020

• Added better time control for Arbiter
• Added more UCI options
• Added Tuner project
• Added insufficient material detection
• Added executable hash generator
• Added abort when search lasts too long
• Added legality checking of the hash table moves
• Added SEE pruning in the quiescence search
• Added fianchetto evaluation
• Added internal iterative deepening
• Added a lot of UCI options, allowing for full engine customization
• Added multi-stage move ordering
• Added multi-stage move generating
• Fixed FEN parser when input didn't have halfmove clock and moves count
• Fixed crash when the engine was receiving invalid position in UCI mode
• Fixed UCI statistics
• Improved time scheduler when incrementation time is present
• Improved mobility calculation by rewarding for center control
• Improved late move reduction conditions
• Improved SEE accuracy (now includes x-ray attacks)
• Improved king safety evaluation
• Changed maximal moves count from 128 to 218 (according to Internet sources)
• Reduced size of transposition table entry (from 12 bytes to 8 bytes)
• Disabled most of the evaluation functions when the game is near to end
• Disabled returning of exact transposition table entries in the PV nodes
• Adjusted evaluation scores
• Optimized king safety evaluation
• Updated .NET Core runtime version to 5.0.100

v2.0 (Darkness), 19.10.2020

• Added fifty-move rule detection
• Added new evaluation functions: pawn shield, bishop pair, doubled rooks, a rook on open file
• Added "evaluate" command to get FEN position evaluation
• Added ability to postpone moves generation before PV move check
• Added evaluation hash table
• Added Arbiter app to speed up the process of testing engine
• Added support for UCI's winc and binc
• Fixed PV node detection
• Fixed invalid detection of passing pawns
• Fixed invalid best move when a search has been aborted
• Fixed static exchange evaluation - in rare cases the table was returning an invalid score
• Improved method of probing piece type at the specified field
• Improved time management - now allocated time depends on the moves count
• Improved move ordering: castling and better promotions are now prioritized
• Improved transposition tables: entries are now smaller, have proper checkmate scores (relative to position) and are used between moves (aging)
• Redefined and reduced the size of Move structure (from 4 bytes to 2 bytes)
• Reduced size of transposition table entry (from 16 bytes to 12 bytes), evaluation hash table entry (from 8 bytes to 4 bytes) and pawn hash table entry (from 8 bytes to 4 bytes)
• Optimized printing UCI output
• Adjusted move ordering scores
• Updated .NET Core runtime version to 3.1.403

v1.0 (Aqua), 19.09.2020

• Initial version