Sjeng : New features

RELEASE 12.0 'Leiden' (2001-11-3)

Much enhanced evaluation.
Improved search, extensions, move ordering.
Improved timeusage.

SEE knows about xrays.
Active pondering.
Failed testsuites are written to miss.epd.
Supports logfiles.

Removed variants code (for now).

RELEASE 11.0 (experimental)

New suicide mode.
New losers mode.
perft reports leaf nodes (like crafty).
Suicide endgame databases.
Fix to movegen (>300 possible moves).
No nullmove on pv.

RELEASE 10.0 (2001-6-6)

Lots of stability improvements.
Minor fix to legal move detection.
Fixes some lockups in suicide/giveaway.
Fixes to draw detection.
Bugfix to time allocation.
Bugfix: may not castle in suicide.
Fix to 'st' command.
Fixes to draw detection.
Castling in giveaway is now recognized.

Constrain book learning a little.
Cull very rare book lines.
Updated losers and suicide OPN books.

Improved speed benchmark.
Endgame tablebase support (Nalimov up to 6 man).
Updated docs.
Full losers support.

More standard chess knowledge (mobility, passed pawns).
Smaller aspiration window.
Detect when nullmove is probably bad.
Less futility pruning in qsearch.
Optimized legal move and incheck tests.
Added bonus for doubled rooks on (half)open file.
King tropisms for normal chess.

RELEASE 9.0 (2001-4-5)

Support for losers's chess.
Tweaks to kingsafety in standard chess.
Recognizes 50-move and 3-rep draws.

Fixed book learning, new algorithm with backpropagation.
Books can be exchanged between Windows/Linux, less memory used during building.

Uses quiescent hashing.
Smarter handling of depth-preferenced stores in transposition table.
Pick new move if search fails high and times out, extend time on fail-low.

Don't disable pruning on some cheking moves.
Static Exchange Evaluation sorting and pruning.
Root move sort based on nodecount.
Reply immediately on a forced move.

Delay in ptells for mating pieces.
Use ghost pieces to anticipate trades.
Partly merged David Dawson's eval.
Inform partner when trades are bad.
Fixed bughouse fast mode.

Workaround for WinBoard/XBoard zippy bugs.
Support for future winboard protocols.
Added detection of Chessbase Winboard adapter.
Support st and sd commands.
More output during analysis mode.
Display settings code on servers.

RELEASE 8.1 (2001-1-5)

Improved move ordering.
Fixed hashing bug.

More aggressive book learning.
More book randomness.

Improved failed search handling.

RELEASE 8.0 (2001-1-2)

Much improved crazyhouse evaluation.
Tweaked search & extensions.

Support for v2 of xboard/Winboard protocol.
Fixes to xboard/Winboard support (setboard, undo).

New suicide mode (no more alpha-beta).
Small suicide opening book included.

Simple book learning.

Use a configuration file.
Use SAN for move output.

RELEASE 7.5 (2000-12-07)

Suicide opening book.
Tweaked bookbuilding code.

Fixes to 'test' command.

Tweaked zh piece/square tables.
Tweaked suicide eval.

Optimized movegenerator.
Faster proof-number search.

Fixed MVV/LVA move ordering.

Better extension control.
Passed pawn extensions.
Don't nullmove in endgames.
More carefull R=4 usage.

RELEASE 7.4 (2000-10-18)

Faster move generation.
Faster search.

Support for suicide.
Full proof-number and proof-number^2 implementation.

2-level Transposition table.

Supports analysis mode for crazyhouse games.

RELEASE 7.3 (2000-6-22)

Faster move generation/Cleaner code.

Better handling of failed searches at root.
Improved forward pruning in search.

Binary book with transpositions.
Automatic bookbuilder.

Better time usage.

Built-in benchmark.

Partial support for SAN moves.

Improved evaluation, bad trade, drawn endgames.
Position learning fixes.

RELEASE 7.2 (2000-4-22)

Fixed out-of-bounds error.

Better support for systems that lack ftime.

Added books and tests to source distribution.

RELEASE 7 (2000-4-15)

Modified piece values as per Gnejs request.

More bonusses on partner tells.

Improved book handling code.
Book selection is no longer fixed for zh/bug.
More randomness in book selection.

Faster fast mode.
No interruptions in fast mode.
Removed depth checks from search timing code.

Penalty for pawns blocking development.

Nullmove R factor is dynamic again.
More strict check limiter, but quiescent lock is now added for all variants.
Re-enabled internal iterative deepening.
Fixed serious bug in DPVS.
Major bugfix to loading of learned data.
Disable nullmove in endgame near root.

Go fast if fellow Sjeng is dead.
Sit if losing a --- piece.
Automatically tell other Sjeng to go if something no longer mates us.
Automatically resign if both dead.
Fix infinite greeting bug.
-/+ p implies b, q
-/+ r implies q
-/+ b implies q

RELEASE 6 (2000-2-20)

Check whether we need to move faster than 1 second in fast mode.

Check-Qsearch lock is now removed in bug/zh.
Limit check extensions. (all variants)

Nullmove depth fixed to R=2.
Disabled internal iterative deepening.
Widened extended-futility pruning window in bug/zh.

Improved transposition tables.
Improvements to move ordering.

Switch f5 between bughouse and crazyhouse depending on whether or not we have a partner.

Fixes to variant-switching code. (would sometimes play zh when it really was a standard game)

Added positional learning code. Will create standard.lrn and bug.lrn and store known positions.
Learning code is disabled if goal time is less than 1 second. No idea whether this really works as intended ;)

RELEASE 5c (2000-1-9)

Sjeng no longer crashes when losing a game with pondering enabled.

EPD code is now enabled. Testsuites can be run automatically with the 'test' command.

Razoring is disabled at ply 1 nodes. May or may not help strength.

Material warnings are reordered to fix a bug when partnering itself. Also fixed the 'sorry' loop that was introduced in the last release. Sjeng should now be quite able to play with itself as a partner.

Minor changes to bughouse/crazyhouse evaluation.
 

RELEASE 5 (2000-1-2)

Ptelling 'abort' and 'flag' will cause the respective command to be sent to the chess server in bughouse mode, 'time' has been aliased to 'fast' and 'move' to 'go' to accomodate for people that don't bother reading the help.

Sjeng will now only sit if mated in 2 or 1.

Whispering is disabled while playing bug.

Fixed a bug with the '.' command while analyzing.
Fixed bugs in edit mode. Analysis, edit mode and takeback should be fully working now.

Removed early-exit on a mate. This allows Sjeng to search on and maybe find a faster mate.

Pondering status is preserved on a new game.

Added move-now support. Users of the Windows version may need to press 'move now' twice.
Added periodic update support in analysis mode.

Added support for X/WinBoard 'st' command (untested).

Fixed bug with changing material values & variants.
Fixed bug with king values (missing sign).

Added status output after searching PV at root level.

Fixed move ordering in internal deepening nodes, but there is still very few gain in using it.
Severe bugfix in history move ordering. This should help performance *a lot*.
Razoring is disabled on PV nodes.
Futility pruning, extended futility pruning and limited razoring were added.

Changed bughouse/crazyhouse evaluation to put more emphasis on dynamic bonusses rather than static ones.

Ptells are discarded in standard mode. Having a noisy partner while playing bughouse could lock Sjeng up.
Piece requests can be handled now, as well as requests for more trades. (i.e. ptell +P, --trades,... )

Fixed longstanding bug with ep squares in standard chess.

Marginal support for draw-by-repetition in the search.