Release History

v2.52 - 6 Aug 2006

• "Check Evasion" and "Re-capture of same-value piece" search extensions re-enabled.
• Bugfix: Insufficient Material draw condition was being incorrectly claimed when both players were down to their last two pieces.
• Bugfix: Fifty Move draw condition was not resetting if a piece was captured.

v2.51 - 6 May 2006

• "Drag and Drop" style user-interface is now be used to move pieces around the board. (Contributions from Nimzo)
• The colouring of chess board squares used to indicate the legal moves for pieces, and also to show the moves that the computer is considering while it is "thinking", have been toned down. (Ideas from Nimzo)

v2.5 - 25 March 2006

• SharpChess upgraded to use version 2 of the DotNet Framework.
• PV debugging code added to source code. - Nimzo
• Killer Move code enahcned to ignore captures. - Nimzo
• Pawn fork conditions given additional weighting in evaluation function. - Nimzo
• Bugfix: Captures were being incorrectly handled in the hash-table. - Nimzo

v2.4

• Help About updated to include a "contributors" section.
• Bugfix: When pasting a FEN position, some pawns would be incorrectly marked as En passant.
• Bugfix: Backup file was sometimes incorrectly named.

v2.3

• The FEN code for the current board position can now be copied to the clipboard.
• King moves are now also cached in the Pawn Hashtable, effectively changing it into a PawnKing Hashtable!
• Standard null-move-pruning enhanced to "Adaptive" null-move-pruning.
• Null-move-pruning switched off in end-game.
• Move ordering is now ordered by:
  
  • Best move from Hashtable.
  • Winning capture exchanges (determined by SEE) and promoted pieces.
  • "Good captures" in order - QxQ, RxR, NxB, BxB, BxN, PxP
  • "Killer Moves" in order - KillerSlot1, KillerSlot1 from 2 plies ago, KillerSlot2, KillerSlot2 from 2 plies ago.
  • "History Heuristic".
• Bugfix: Fixed an error in the hashcoding of promoted pieces, which was causing illegal moves to be generated in some rare positions involving checks with promotions.
• Bugfix: Major error in SEE routine was causing it give wrong values of captures (Thanks Nimzo).
• Bugfix: It now possible to paste "partial" FEN positions. Only the first of the six fields is mandatory. (Thanks Nimzo).
• Bugfix: When pasting a FEN position, where Black is on move, Game move number would be out by half a move. (Thanks Nimzo).

v2.22

• Bugfix: Fixed a bug where the clock only starts after white makes it's first move. Clock now starts when a new game begins.
• Bugfix: Fixed an error in updating the progress bar that was causing SharpChess to crash.

v2.21

• WinBoard "setboard" command now supported.
• WinBoard "analyze" command now supported.
• Bugfix: Castling rights for Kings rook not being correctly set for FEN positions.
• Bugfix: Simple opening book would select moves for the wrong player.
• Verified Null Move Forward Pruning reverted to Standard, again.

v2.2

• Menus have been re-structured and are now, hopefully, easier to use.
• FEN positions can now be pasted from the clipboard. The FEN position is also recorded in savegame files. Major contribution from Nimzo in this feature.
• Added WinBoard OTIM command. This makes the opponents clock update correctly within the SharpChess GUI, when playing WinBoard games.
• Added support for WinBoard fixed-time games. This will handle fixed "x" minute games that have no set number of moves and no time increment per move.
• Verified Null-Move Forward Pruning, is back in again!
• Bugfix: A particularly elusive bug causing intermediate board positions from the computer's thinking to be shown, leading to intermittent crashes, has now been fixed. Hurray!

v2.1

• The Prinical Variation (the best line of move SharpChess finds while thinking), is now recorded during thinking, and displayed in the status bar.
• Major re-structure of "Think" and "alpha-beta" functions to eliminate duplicate code fro "Think" and move it down into a single neater alpha-beta function.
• Verified null-move forward pruning removed, and replaced with normal null-move forward pruning.
• Search extensions (as part of main search) added: Check Evasion, Single response, Pawn push to 7th rank.
• Move description shortened in move history, and status bar. Thanks Nimzo.
• Resizing of Move History pane improved. Thanks Nimzo.
• Bugfix: Crash occured when using File-<Exit to close program while computer pondering. Thanks Nimzo for fix.
• Bugfix: Redo menu option and shortcut key weren't working.
• Bugfix: Crash occured when loading game with moves that took more time than that remaining on the clock.
• Bugfix: Menus "Redo Move", "Undo All Moves", "Redo All Moves", "Think" did nothing. Fixed by Nimzo.

v2

• SharpChess.exe renamed to SharpChess2.exe, in order to avoid conflict/confusion with another, older WinBoard chess engine named #Chess, written by Albert Bertilsson. #Chess also used the filename "SharpChess.exe", which caused conflicts when competing in WinBoard tournaments. The next release of SharpChess, will jump straight to v2.0.0
• For WinBoard games only: Added of 50 move and insufficient material draw detection. SharpChess will now claim both these types of draw when it, or its opponent, moves into a draw position.
• For WinBoard, added support for WinBoard "level", "st" and "time" commands, so that time modes: Tournament Clock (n moves in x mintes), Incremental Clock (x base mintes + y seconds-per-move), and Fixed-time-per-move, are all now fully supported.
• SharpChess now starts minimised when running from WinBoard.
• WinBoard Message Log and Move Analysis windows updated to "Show In Taskbar".
• BugFix: Rank and File Board labels weren't being moved when the board display was flipped. Thanks Nimzo for this fix.

v0.942

• Bugfix: Added extra checking in WinBoard interface to stop thinking/pondering when certain commands are received at unusual times.

v0.941

• WinBoard protocol v2 now supported.
• Increased penalty for king losing casting rights.
• Bugfix: Fix error in not setting computer player back to playing Black after "new" command received.

v0.940

• Completed WinBoard integration. SharpChess.exe can now be used as an "engine" in WinBoard, so that SharpChess can automatically play against other chess programs, and play over the internet. See the WinBoard WebSite for more details about the features of WinBoard and WinBoard-compatible chess programs.
• Added new floating WinBoard Message Log window that can be used to watch communication messages between SharpChess and WinBoard.
• Converted the Move Analysis tree display into a floating window, rather than it expanding out of the side of the SharpChess main window, as it did previously.
• Added option in Difficulty Settings to switch random opening moves, from opening book, on/off.
• Increased thread priority of pondering thread to normal, from below normal, as I found other chess engines were "stealing" SharpChess's pondering CPU cycles!
• Bug fix: Improved the way SharpChess detects if it has been launched from WinBoard, as it was sometimes failing to detect this correctly.
• Bug fix: Fixed synchonisation bug, where pieces would briefly appear in wrong positions while the computer was thinking about its move.
• Bug fix: Fixed "Piece already promoted" error that occured when WinBoard interface promoted a pawn.

v0.930

• A setup program has now been created to install SharpChess.
• Pawn promotions to Rook, Bishop and Knight, as well as Queen, are now possible. SharpChess will now also consider these moves when it is thinking.
• Changed material totals in captured piece tray to be the total value of pieces remaining in play, rather than the value of pieces captured. I feel this is more accurately takes into account promotions in the balance of play.
• Re-wrote some the pondering and side-to-play control code, in order to move it from the user-interface back down into the chess engine, where it should be. This will make WinBoard integration easier to achieve, as well as improving the ease of future development and maintenance.
• Bug fix: Player status of checkmate, stalemate, check etc was being lost from the Statusbar and move history after a Redo Move command. Now fixed, thanks to Nimzo.
• Player status is now also displayed next to the game stage readout.

v0.922

• Split the duel-purpose "Force Computer Move" button, into two separate buttons: "Move Now", which forces the computer to stop thinking and move immediately, and "Think" which causes the computer to play a move for the current side-to-play.
• Bug fix: Double-clicking "Force Computer Move" caused a crash.
• Bug fix: Altering difficulty settings whilst the computer was thinking, wouls sometimes cause a crash. Difficulty Settings option is now greyed-out while the computer is thinking.

v0.920

• Added a "Difficulty Settings" form that appears when you start a new game, and can be accessed from the Options menu during play. The form enables the user to select from 16 preset difficulty levels, or to set their own custom difficulty settings. In custom mode, the user can now modify:
  
  • Thinking Time.
  • Maximum Search Depth.
  • Enable/Disable Pondering.

v0.910

• Reduced the size of the SharpChess chess board and main program window to fit into 800x600 desktop resolution.
• Changed the two score indivators that display the total value of material remaining for each side, to be total value of matieral captured, and reposition them to the right of the captured piece bay.
• Enhanced Quiescense searching extend capture search lines where a piece is attacked by a piece of lower value, or is attacked and not defended.
• Changed Pondering to be off by default, when SharpChess is run for the first time.
• Bug fix: Corrected recent bug on registry reading code that would cause SharpChess to crash at startup, on machines that had not previously had SharpChess installed.

v0.902

• Bug fix: Improved thread communication between the "thinking" thread, and the main thread, by using Control.Invoke calls to update form controls.
• Bug fix: Program was locking-up when accessing the options dialog if the computer was pondering.

v0.901

• Add a built-in 1303 position 8-ply deep Opening Book, in order to add more variety to SharpChess's initial moves.
• Tweaked (probably just implemented properly) the verified-null-move-forward-pruning code and gained a whole extra ply of search depth!
• Added 2-slot killer-move enhancement to the search algorthm. Noticed only perhaps a 3% improvement in search times.
• Updated the user-interface design, when the user switches off 'Show Thinking', less information regarding moves being considered, and their scores, is displayed.
• Changed the default clock time to 120 moves in 20 seconds, to make SharpChess seem "faster" to first-time users.
• Save game files now include moves that are in the redo buffer.
• Save game file format altered to make the from and to moves more human-readable.
• Bugfix: Extra erroneous "pondered" moves were being included in backup savegame file when program was closed.
• Bugfix: Corrected three-move-repetition problem, where the side moving in to the draw position wasn't considered to be able to claim a draw, in that same turn.

v0.087

• Bugfix: Fixed "Arithmetic operation resulted in an overflow" bug that occured when loading SharpChess on versions of MS Windows that do not support fully Perfomance Monitoring. Problem occured mostly on Windows 98, ME, 2000 Workstation editions.
• BugFix: Fixed slight performance penalty "bug" that was caused by me accidently "REMing-out" the 'In-Check' hashtable optimisation code!

v0.086

• Bug fix: Computer was incapable of checking or capturing pieces with it King's Knight.

v0.085

• Bug fix: Stopped computer moving into a three-move-repetition positions.
• Bug fix: Promoted Queens were incapable of checking enemy King.
• Bug fix: Stopped sharpchess crashing on checkmate when running in .NET 2005 Beta.

v0.084

• Flip board to play as White or Black.
• Player Human/Computer settings now saved with savegame file.
• Board orientation now saved with savegame file.

v0.081

• Added optional "Pondering" feature. The computer can now by made to think during its opponents turn time.
• Improved move search depth/speed.
• Backup game saved after every move is played. Last backup is reloaded each time SharpChess is run.
• Completed n moves in x minutes clock game-time controls. User can now use this to control the amount of time that the computer spends "thinking".

v0.791

• First public release