History

Rodent III 0.172 Another rewrite, implementing multi-threading (up to 4 threads). Evaluation and options similar to that of Rodent II, pawn play a bit more solid.

Rodent II 0.9.64 for Windows (polyglot opening books, personalities, 64-bit Windows compiles, source code ready to be compiled under Linux)
- UCI Elo option implemented (not sure if it is well implemented, but it works)
- a set of 30+ new exciting personalities
- importing a couple of opening books by Pavel Hase (http://www.chesspraga.cz/spikebook.htm)
- opening book can be set in the personality file now
- UCI options react to loercase version as well
- three alternate piece/square table sets. Default (PstStyle 0) has been taken from Hakapeliitta, made symmetric and tweaked. PstStyle 1 is the previous set of tables, modified version of Fruit/Toga tables. PstStyle 2 comes from Joe Velasco (http://www.talkchess.com/forum/viewtopic.php?t=50840&postdays=0&postorder=asc&topic_view=flat&start=60) and is a simplified version of tables from the Ippolit and company.
- two alternate mobility table sets. Default (0) is from good old Fruit (via Toga Log User Manual), the second one comes from Fruit Reloaded. Both changes increase the number of possible playing styles.
- tweaking mobility values and conditions (in short, no bonus for defending own pawns)
- bugfix of check threat eval (no threats from squares occupied by own pieces)
- internal iterative deepening in cut nodes
- escapes from a capture refuting null move are sorted higher
- evaluation of castling rights in the opening
- discovered checks by knight are generated in QuiesceChecks()
- bugfix of static draw detection routine
- razoring tweaks
- mobility tweaks
- conservative LMR of bad captures (one ply)

Rodent II 0.9.33 for Windows (polyglot opening books, personalities, 32-bit and 64-bit Windows compiles, source code ready to be compiled under Linux)
- more stable quiescence search
- more endgame knowledge, including unstoppable passers
- limiting check extension
- adding recapture extension in pv nodes
- retuning some eval parameters, including passed pawns values
- half-open files are less valuable if enemy pawn on a file is defended
- queen is less valuable with enemy minor pieces on the board
- internal iterative deepening in pv nodes
- mate distance pruning
- opening book can be defined in personality file (depending on basic.ini settings)
- new stylistic parameters for keeping pieces on board

Rodent II 0.8.7 (source code, opening book, personalities, 32-bit and 64-bit Windows compiles)
- complete rewrite
- new set of personalities

Rodent 1.7 (source code, opening book, personalities, 32- and 64-bit Windows compiles)
- no lazy eval
- move sorting improved
- many more pawn eval terms, including pawn chains evaluation
- many more stylistic tuning possibilities

Rodent 1.6 (source code, opening book, personalities, 32- and 64-bit Windows compiles)
- root node logic rewritten
- hash score retrieval logic rewritten
- continuation moves are back and they work
- removed some counterproductive code

Rodent 1.5 (source code, opening book, personalities, 64-bit Windows compiles)
- this version is buggy and hangs sometimes towards the end of the game
- fixes and additions in drawish endgame recognizers
- getting rid of a buggy implementation of continuation moves
- more logical handling of LMR in case of very late moves
- bugfix in candidate passers detection
- move routines are now part of position class
- more restrictions on eval pruning
- king tropism eval (style addition)
- always verify null move

Rodent 1.4 (source code, opening book, personalities, 32- and 64-bit Windows compiles)
- important bugfix of weak pawn eval
- hidden passers eval
- deleting buggy pruning of pawn captures
- tuned late move pruning
- internal iterative deepening at cut nodes
- a couple of minor optimizations (i.e. reuse null move eval in razoring)

Rodent 1.3 (source code, opening book, personalities, 32- and 64-bit Windows compiles)
- move ordering tweaks (refutation and continuation moves)
- second competitive king safety function
- contempt
- setting filter threshold for Polyglot opening book
- options for personality setting are more or less complete now

Rodent 1.2 (source code, opening book, personalities, 32- and 64-bit Windows compiles)
- LMR tuning
- polyglot book support
- yet another king safety refurbishing


Rodent 1.1 (source code, opening book, personalities, 32- and 64-bit Windows compiles)
- much better LMR
- new, too conservative king safety
- tuned passed pawn eval
- a couple of small eval tweaks

Rodent 1.0

- source code, opening book, personalities,Windows, Linux, Android and 64-bit compiles by Jim Ablett
- this version earned number 1.0 by beating Fruit 2.1 in a 100 game match

Rodent 0.18

- rather embarassing bugfix in static exchange evaluation
- evaluation of hanging pieces (inspired by DiscoCheck - thx Lucas Braesch and long live open source)
- passed pawn eval taking into account blockage and control of the stop square (finally works!)
- improved time management (easy move and some safeguards triggered by extreme time shortage)
- marginally better move ordering (a side effect of quiescence search tt entries left after looking for an easy move)
- asm popcount for 32-bit architectures (5% speedup)

Rodent 0.17

- maintenance release
- null reduction depth bugfix (spotted again by invaluable Kestutis Gasaitis)
- some tinkering with aspiration window
- candidate passers eval
- some bugfixes in checkmate eval and material eval

Rodent 0.16 - rollback to v. 0.13 and adding features from two previous versions
- minor speed optimizations
- restructuring of options
- many bugfixes, thanks to code inspection by Kestutis Gasaitis
- some new pruning
- better pawn shelter eval

Rodent 0.15

- misguided, weak version (self-play results turned out in the wrong ballpark) - position learning

Rodent 0.14

- opening book support

Rodent 0.13

- "the golden oldie", beating next two versions
- fixed ugly time mangement bug, preventing Rodent from playing x moves in y seconds repeating
- new king safety evaluation, resulting in less boring games
- weakening mode (1200- 2600 Elo, untuned)
- a couple of eval additions and bugfixes

Rodent 0.12

- version with time management bug, unfit for repeating time controls

Rodent 0.11

- two-tier aspiration window
- tuning of some eval parameters
- small part of history value (used for move sorting) is carried over from previous search
- bugfix of move generation cache

Rodent 0.10

- a little hurried update, nothing spectacular, perhaps +30 Elo
- no "extern inline" rubbish
- KRK checkmate bug corrected
- simplified mobility evaluation
- late move pruning near the leaves
- static null move near the leaves