Initially the end-game-databases supported by the Lokasoft standard engine are mainly made by Ken Thompson, an American Pioneer in this area who already in 1975 performed revolutionary study and tests. In that period he developed endgame databases with 3 and 4 piece endgames. The endgames using 5 pieces where developed later on. In other words, endgame databases are around a long time but it took a while before (commercial) programs make use of them. This is mainly due to the large size a database may take. 100 Megabytes are not unusual for a single database file. Now that CD-ROM are accessible to almost everyone, the endgame databases find their way to the public through this medium. Considering the size of this multitude of files (currently 4 CD’s full!) a fast CD-ROM player makes sense. Quad or six speed drives are recommended although single and double speed will work.

 

Since a few year the Nalimov endgame table bases are standard supported. Advantage of the Nalimov endgames are they give the distance to checkmate whereas the Thomson tables give the distance to conversion.

Definition

An ‘End game’ position “calculated up to mate or draw is about the shortest description we can give but it does not cover it in full. simply looking up the best variant for a certain position seems the way to reach the end. There are however, many ways (longer) to get to the end. An end game database is therefore build differently. Each position has the number of moves that will lead to “conversion”. Conversion means where the material or amount of material changes. In other words; when a piece is removed from the board or promotion occurs. After conversion a new end game situation exists and requires a different database to access.
When you provide the best counter-play against the database the “finale is as far as possible”. When played ‘worse’ than opposed the end will be nearer!

5 Piece end game

Such an end game has of course the black and white King plus three other random pieces. Theoretically all these positions can be calculated till the games finale. This is a tremendous job and till date only the most relevant kind of piece combinations have explored. Its only a matter of time before the others appear.
In a number of cases we must ignore the 50-move rule to come to an end. This is not according to accepted Chess rules but from a scientific point of view, interesting. The program offers the option to ignore the 50-move rule to enable you exploring several end games that require such. Note: Not all engines support this function.

Using the end game database

In order to use the (Ken Thompson) databases you’ll need to turn on this feature through the Chess brain options. Additionally you will need to define the drive(s) and path(s) where the databases can be found using the Advanced.,. engine options.
Note that the program may be delivered with or without End Game CD-ROM’s depending on your supplier and price! The Internet distribution does NOT come with the CR-ROM’s

Place the CD-ROM in the CD player. In case you have multiple CD-players you may use multiple end game CD’s simultaneously. When you have a CD-ROM Jukebox do NOT use multiple End Game CD’s, the swapping of discs takes too long for correct functioning. Further action on your behalf is not required, except moving the game to a 5-piece position of course...
From that moment on, when it’s the computers turn, the position is checked to be present in one of the databases. If so, you are prompted to put the appropriate CD into the drive if not already present. Next the database is queries for the best move. During the search you may be asked to put in another end game volume since the position may convert into a different game.
When the position is present in the database, the Statistics window will show it. It will occur that multiple best moves exist for a certain position. Using the Next Best feature you can evaluate these paths. The Statistics window indicates the presence of next best moves where variant moves are between brackets.
Since the database is constructed to seek for the shortest distance to conversion in the first place and mate in the second, it may occur that mate can be reached sooner than the database will show! End games where a pawn (7th row e.g.) has an important role are good examples.
 

Nalimov table bases

What has been said about the endgame databases from Ken Thompson, in general also applies to the Nalimov table bases. It is recommended to store the table bases on a fast hard disk. The Nalimov table bases are also configured in the Advanced.,. engine options page.

Multiple paths may be given separated by semi colon. No matter what path you fill in, the directory where the program is installed is always searched first. Standard the program comes whit all the 3 piece endings ( K+K+piece). Other endgames can be downloaded from the Internet. Check our website for the location.