Changes

If the opening database designer has some special preference of a certain opening line, he might create it fully manually. This is often the case if a chess program is about to play an important game against a grandmaster. Then the opening style will probably be chosen to be difficult and dangerous for the opponent. Another option is to first automatically generate a database and then fine -tune it manually.

==AutomatedFrom game collection== Another option is to select a number of games (the type of which will effect affect the openings played: e.g. drawn games only, GM games only, etc) and then up to a certain depth store all positions in the opening database. It is true that by using this way of database generation some severe errors might by copied as well, but usually the chess programs are set to stop playing according from to the book if a position occurred less than a certain number times before.

==By computing==Chess [[engines]] can be used to evaluate positions in a book opening tree to rank them, and/or decide to stop or expand. =Book Building Tools==