Slow Chess Blitz, a free chess program
by Jonathan Kreuzer

web: www.3dkingdoms.com/chess/slow.htm

Main Help
Internet Options
Using as a Winboard/UCI engine


Using Slow Chess:

Moving Pieces: If it's your turn and you click on one of your pieces, it will be selected, and a white box appears around it. Then just click where you want to move it. Castling is done by clicking the king, then the square where he would end up after castling. En Passant captures are performed by clicking the pawn and then its destination square.

Side Window
Move button: Tells the computer to stop thinking and play the best move its found so far if it's thinking, otherwise it will tell the computer to start playing as the side to move.
Analysis button: Start infinite analysis, see Analysis heading for details.
Book button: Highlight on the board all the moves in the Slow chess book from this position.
Retract button: will take back the players last move so that he can make a different one.
< and > : will move a half a move backward/forward respectively.
<| and |> :will go to the first and last move of the game.
Clicking on the transcript will set the board to the move clicked on.

Search Options:
The Difficulty level uses all limits set. Use 'user-defined level' to set these limits. (Let's say it's set to 7 ply, 5 seconds. If it completes a 7 ply search before 5 seconds it will stop, otherwise it will stop after 5 seconds no matter how far it has searched.) The 28 ply is meant to be used for time based games, since it will always (except certain endgame situations) reach the time limit before it reaches 28 ply.
Seconds per move defaults to 0, and when it's set to zero the computer uses the time control to choose how long to think about its next move, instead of thinking a set amount of time per move.
Ponder Next Move: When checked, the computer will continue to think about its next move even when its your turn. When unchecked, the computer will only think on its turn.

Personality: You can alter the playing style by using Menu->Search Options->Personality. The default personality uses symmetric evaluation for black and white and is therefore best for analysis, other personalities use asymmetric evaluation (eg. Aggressive values king safety less for its own side than for the opponent's side.)

Displayed Search Info: When the computer is thinking, it will display info about the search unless this option is unchecked. It will display the furthest depth to which it searched a move completely (with a * afterwards if not all moves were searched to that depth, a * after the eval value means there's no value for this move at the current depth), the number of nodes it searched, and search speed in Kilonodes/sec, and the evaluation value of the best move.
(e2-e4)1.5/20 means there are 20 legal moves, and Slow is currently searching the 1st of these (e4) and is searching the 5th of the opponent's responses after e4.

Analysis: To start analysis of the position currently on the board, click the "Analyze" button in the side window. A window will appear below the board which will display the principle variation of the best move or best moves found. Positive scores are good for white, negative good for black. If you don't mind much slower best move analysis, you can use the '+' and '-' button to have the computer calculate the 2nd best - 6th best moves in addition to the best. You can also turn on the analysis window while playing against the computer from the options menu.

Edit Menu: Slow Chess supports PGN and FEN, popular formats complete games and single positions.
Copy Position copies the position on the board to a text FEN string on the Windows clipboard.
Paste Position will set the position from a FEN string.
Copy/Paste Transcript converts the current game to/from PGN strings on the clipboard.
Copy/Paste Game State are there so you can copy the game state, explore a variation, then paste to get back to the old game state.

Time: The large print top clock is the time left for a player to complete his move (according to the time limit set on the menu.) The bottom is the total time the player has taken to make his moves so far. Use Menu->Time Control>Set Time Control to set the time limit. It will be used for both players, computer or human, although humans are free to ignore it. If the time left runs out, you would lose the game by the rules of chess, but here your clock just stays at zero and you're free to continue to play. Time is reset anytime you select "Menu->Game Actions->New Game", or "Menu->Time Control->Reset Clock"

In the window beneath a player's time, 1R, 2p beneath black's time would mean that black has 1 more rook than white, and 2 more pawns.

Hash Size: Most chess programs store a table of positions from the search in a "hash table" to speed up the search. Use Menu->Hash to set this size. The limit set will be used for games in the Slow GUI and those in Winboard. You can use the "Menu->Hash->Clear Hash" to clear this table (mainly for resetting state for test positions, etc.)

Endgame Bitbases: Bitbases must be in the same directory as the .exe to be used. If they are not present they will be ignored. The bitbases contain information on whether certain endings are won/drawn/lost. For instance the KPK.sbb comes with the .exe and tells whether the side with the pawn has a won game or not, and is quite small at about 15kb. (Older Slowchess versions use an incompatible 24kb version.) Other bitbases are available as a download from the web page. The KPPKP.sbb only contains information where opposing pawns are locked, but the rest contain all information needed for endings with those pieces. To test if the extra bitbases are working, here's a position where Slow should instantly show a draw score: 8/8/p6p/P6k/8/5K2/8/8 w - -

Note on the opening book: You manually add or remove positions from the opening book with the 3 and 6 keys. (Also 1 or 2 keys = position preferred by black. 4 or 5 keys = position preferred by white.) Remember to Save the book when you're done, it never auto-saves. You can also add .pgns to the book. If you load an opening book the positions will be added to whatever is in the book in memory. Slow Chess can't handle really large books. 

Using Internet options:

(Note: I of course don't presume that the internet play is bug-free, but I have tested it, so it seems to work okay for me so far.)

Make sure you both have the same version of Slow Chess, preferably the version on this page. If you are not familiar with computer networking/internet connections, you may have to brush up on this elsewhere to get this option to work for you. As this subject varies with your individual hardware&software, all issues are not explained here. 

One player selects "Start Server" from the internet menu. This will start a Slow Chess server that will listen(wait) for connections. Whoever starts the server will be automatically connected as a client (player.) 
Once a server is running, to connect to the server to play other clients, choose "Connect" from the internet menu, and type the ip of server in the pop-up and hit connect.
Up to 32 clients may be connected, but I haven't tested it with more than 4 or 5 people.  
Slow Chess uses port 14324.  If you are behind a router/firewall, and want to have someone connect from the outside internet, you may have to open this port and direct it to the computer that is running the Slow Chess server. Also you will need to give the external ip for people to connect to.

Commands are provided through the Game Actions menu and the Internet menu.

Using Slow Chess as a Winboard Engine: (Skip this part unless you have Winboard and want Slow Chess to use it instead of its own GUI)

Slow.exe can be used as a winboard engine the same way as any other. Slow Chess only supports protocol #2, it doesn't support older winboard versions. Versions 2.93a and later also support UCI. Because it makes things much simpler for me to have only 1 .exe to update, I don't have a separate console winboard version.  The only thing I've noticed because of this is there's an hourglass next to the cursor upon startup for a few seconds. Also note that Slow Chess saves its games under winboard as winboardgames.pgn in whatever directory it is run from. I just wanted to keep all the games it played, you can delete this file any time you want. For those who like to know the country of their winboard engines, Slow Chess' official country of origin is the United States.

I've mainly tested Slow Chess computer versus computer matches in the winboard GUI, over the past year version 2.89b to the latest have played over 1000 blitz/bullet games on my computers without problems (no crashes, or time losses when time control had an increment.) This doesn't mean there aren't bugs, but it has run fine for me. Other GUIs are not as well tested.

You can freely get these winboard compatible GUIs. Winboard homepage, Arena homepage.

The Fritz GUI has some issues when running UCI engines.

Delayed/slow analysis: When using create UCI engine, you can check the Slow UCI option "low priority." The Fritz GUI requires engines to run at lower priority, or it may delay displaying thinking lines until well after they're received. Its method of changing engine priority doesn't work on Multi-threaded engines like Slow Chess. As long as no other programs are running it will only be a couple percent slower than in other GUIs, and Fritz will display the thinking lines when it receives them.
Note that the lower priority makes engines more susceptible to other running processes taking up most of the CPU for a move and causing blunders.

Other Issues: Ending an engine name with a "." could cause an error in the Fritz GUI, so the name of Slow Chess Blitz no longer ends with a '.'
The Fritz GUI sometimes tells UCI engines to use 1 MB of hash for no reason, this command is ignored by Slow Chess, but could cause the hash size not to change to the set size.