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=December 2014, Version 1.1= - LMR added - eval pruning added - major cleanup of evaluation function - new king attack function - new futility pruning restrictions

=September 2008=

05.09.2008
- display of book alternatives - FIX concerning illegal book moves - NEW: book moves can be selected by their frequency

04.09.2008
- a couple of int functions whose returned value has not been used renamed to voids - clearing of the search driver now done in search_run, not in time_xxx_go - more comments

03.09.2008
- in search procedures renamed smove m[256] to smove movelist[256]; "m" should be reserved for a single move - move_isPseudoLegal replaced by move_isLegal which tests for check

02.09.2008
- NEW: search_iterate stops on one legal reply after searching to depth 4 - new names and location of functions move_isPseudoLegal and move_countLegal - more comments in search.cpp - separated book.h - FIX: replies to moves excluded from the opening book ( again )

=August 2008=

29.08.2008
- small internal book (in case that book file is missing) - FIX: timing-bug

27.08.2008
- FIX: various bugs occuring in fast time controls - only legal moves are checked at the root - FIX: hash memory allocation change possible total memory = hash + hash/4(pawn hash) + 4mb(opening book, etc) - FIX: communication bug, stealing cpu of opponent - FIX: en passant flag is not set when no pawn can execute en-passant capture ( which helps with opening book and increases the number of transposition table cutoffs ) - change in delta pruning - a couple of range checks added - numerous opening book code fixes - simplification of move parsing routine - because of ChessWar, reintroduced badCapture pruning in quiescence search

26.08.2008
- NEW: program can use a TSCP-like book, exclude some moves out of it and handle transpositions - changed time management + comments

26.08.2008
- NEW: program can use a TSCP book and handle transpositions

25.08.2008
- FIX: removed all compiler-warnings (more attention given to variable types) - FIX: correct output of mate-values - FIX: transposition-table crash fixed, when size set to 0 - FIX: ==/= bug in eval.cpp - encapsulation of useKiller - slight changes with futility-pruning - created header file for transposition-table - NEW: 4% speedup through prefetching the transpositiontable entry

22.08.2008
-FIX in pawn shield evaluation "=" replaced by "==" (aaargh!)

21.08.2008
- new pruning in QS (testing if a queen capture and/or promotion can improve alpha)

19.08.2008
- NEW: evaluation hashtable (currently disabled, since lazy eval performs much better, but might become useful after a rewrite of evaluation function) - finding good configuration of compiler switches

17.08.2008
- further restructuring of search routines - NEW: aspiration search

16.08.2008
- separating setKillers function

12.08.2008
- serious restructuring of root search functions (sepatating search_root and search_iterate)

10.08.2008
-FIX: hash moves from lower depths used for sorting

08.08.2008
- NEW: contempt function instead of constant

07.08.2008
- NEW: adaptative null move pruning - FIX: loop counter for killer moves initialized as 0, not as 1 (bad Pascal habits!) - FIX: in info_currmove first move number is 1, not 0 (bad C habits!) - in search variable move_to_make instead of a loop redetecting best move - in movegen.ccp vectors represented as constants (NE etc) not as numbers - in movegen.cpp unnecessary int functions changed to void - getting rid of is_futility compiler switch

05.08.2008
- NEW: Pawn-hashtables - NEW: fast_eval - because of that changes futility pruning gives some benefit, so it's enabled now - added move_iscapt and move_isprom to improve readability

04.08.2008
- NEW: function slavMistake that discourages blocking the center - NEW: futility pruning (currently disabled, as node savings do not offset speed loss)

=July 2008=

03.08.2008
- separating com_nothing function - more customizable evaluation parameters

30.07.2008
- NEW: CPW.ini stores evaluation constants - Transposition table: The size is scaled down to the next lower power of 2 - thus replacing the slow mod operation by a quick 'and' operation when generating the tt-index - reducing the tt-entry size from 24 to 16 bytes. (changing alignment) - stop tt_save from overwriting an entry with the same position of a shallower depth - com (uci-protocol): 'setoption name Hash value n' works now

28.07.2008
- TWEAK: reducing a score jump caused by castling - TWEAK: bringing down mobility scores and second lazy evaluation limit - TWEAK: penalty for the lack of pawns

26.07.2008
- TWEAK: raising piece/square scores - TWEAK: modification of evalFianchetto

22.07.2008
- NEW: history heuristics - TWEAK: doubled pawns do not count as a double king's shield - TWEAK: expanded pawn center evaluation: support for e4 pawn also counts

21.07.2008
- NEW: basic fianchetto evaluation - NEW: console interface will accept only pseudo-legal moves

20.07.2008
- NEW: killer heuristics (ugly code in need of redesign, but gains a couple of percent nodes) - FIX: nodes per second calculation overflow problem fixed - NEW: more human-friendly output in console mode

19.07.2008
- NEW: console mode reacts to "st" and "sd" commands

18.07.2008
- separating the eval.h file for function not used outside eval.cpp (better encapsulation) - making use of 088_math.h and changing most of its functions into macros - TWEAK: rooks on open files near the king increase tropism - scaling of middlegame king evaluation affects also pcsq score - creating a eval_vect struct collecting partial scores - serious restructuring of eval.cpp - creating printEval function giving some insight into evaluation components - FIX: fixed a bug with delta pruning (it does not prune promotions anymore)

11.07.2008
- better time management - FIX: time check done once every 1024 nodes, not in each node - massive speedup - optimization of doubled pawn eval (a table instead of multiple ifs)

10.07.2008
- NEW: PVS added - FIX: a check extension also at the root (hash results from a move ago will be used more consistently) - separated PIECE_VAL and SORT_VAL, simplifying the code and getting rid of problems with king value - in fillSq and clearSq the count of pawns on a file is kept, so doubled pawns and open files are finally evaluated - fillSq and clearSq don't update piece/square value for a king (this is done within eval.cpp)

01.07.2008
- FIX: check extension bug fixed

=June 2008=

30.06.2008
- FIX: leaf node hashing bug fixed - some move sorting experiments

29.06.2008
- repetition detection - from now on CPW becomes a chess engine (as opposite to almost-chess engine) - FIX: solved the bug with the hash-values when time is over (tt_save only saves the hash, when time_over == false) - FIX: solved the bug with the communication - null move implemented


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