Menu: Edit – Openings book – Import games
This is a very powerful function. It allows you to build giant opening trees with a minimum of effort. You can, for instance, import all the games of your main database, or all from a specific variation (to create a highly specialised book).
The games of the database will be merged to a tree of positions. Crucial for the size of the resulting tree is the length of the variations which are put into the tree. It is not very meaningful to put entire games into it, so you should truncate them at a specific point.
The program allows you to limit the length of the variations in two different ways.
You can specify that every variation should be “n” moves long. It is more sensible to limit the variations relative to the ECO classification. This results in long variations for theoretical main lines (ECO classification position found late in the game) and short variations for side lines (i.e., early deviations).
Obviously, if you choose a shorter length – absolute or ECO-relative – the tree will be compact. But then you are liable to lose some valuable information. If you choose a very large value then the tree will be gigantic, and it will contain a lot of superfluous information. A good practical value for importing games is ECO-relative 20.
You can also include variations (i.e., analysis that might be included in the games), but these are not included in the statistical analysis.
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