This is often the case if a chess program is about to play an important game against a grandmaster. If the opening database designer has some special preference of a certain opening line, he might create it fully manually. But to achieve this there are two main ways. To build and/or edit those opening books, users need to use special software.Īll in all the information stored in an opening database should guide the chess game into a type of middle game in which the chess program proves itself most successful. So when a chess program has to decide on a move, it will look up (by using binary-search) using the hash value of the current position to collect all information come with that hash value and then make a decision upon it. Items of a book should be sorted by their hash. For example, PolyGlot uses 16 bytes for each item, including hash, move, weight, learning values. To save space those extra information typically about 2-8 bytes. Often each position is stored as a hash value (8 bytes) and some extra information such as the number of times occurred, number of games won by white/black / drawn with this position, average/maximum Elo of players playing to this opening position, chess program's success with the position. However, the major number of top books is built and worked with hash values from transpositions.
At the most simple form, they are just a conversion of above text-opening books into binary, in the ready form for software and save text-binary converting steps.
It may lose temporarily material for long term advantage. Provide a higher quality of play: Searching even with large depths can't see deep tactics, strategy, compensation.In contrast, opening books can play opening moves almost instantly without searching nor heavy computing and help to save time. Save time: Chess programs could use search from the beginning and look through all possible continuations in detail to find the best next move, but as this is quite time-consuming.