ChessSpider!'s Web is a utility which allows one to search for games in their opening repertoire. One can set the White and Black positions they are interested in, select a .pgn (Portable game notation) file, and the system will retrieve the games in which the user defined positions occurred in the .pgn file.
The application is very easy to use. Before running ChessSpider!'s Web, the user sets up 2 text files. This is done only once. Both these files will contain algebraic chess moves in .pgn format. For example, a sample White text file could contain the following moves:
So, the White and Black text files contain moves, but each line represents a position i.e. the position that occurs after the line's moves are played. In this way, transpositions can be handled easily so that if we had the below:
these two lines represent the same position and are interchangeable. One will obviously choose the most personal move-order. Duplicate positions like this are allowed, of course, but it is obviously not useful. If a user inputs an illegal sequence of moves in either repertoire file, the system will point this out when the file is parsed.
After defining the White and Black repertoire lines (positions), these files can be kept intact (or modified when desired). When, for example, a new .pgn file is obtained from one of the various online sites, for example, these same files can be reused and the new games with the user's repertoire positions will be obtained.
One other criterion that affects the resulting games obtained is the Minimum Elo field. To ignore this field and get all games with the specified positions, this field can be set to "None". However, more advanced users will want to set this to a meaningful value. This would mean that for a game to be selected, besides having the positions match, both players would also need to have at least the minimum Elo specified by the user.
After selecting the White and Black positions files, the graphical representations of the positions read will be shown beneath the respective file selectors. The user then selects a local PGN file and specifies the minimum Elo desired. After that, the Get Games button will do the magic! ChessSpider!'s Web can handle heavily annotated .pgn games, so that if one of the selected positions occurs within a variation, the game is picked up too.
When the games are found, the White and Black filtered .pgn files are saved on the server in a .zip file. The user will be informed of how many White and Black games were found and they can click on the "Download" button and, for the token price of €1 (irrespective of the number of games found), they will be able to download the filtered games.
Below are two sample repertoire files, one for White and one for Black. The user can download these files and use them in ChessSpider!'s Web. These files may obviously be modified to contain the user's repertoire positions.