The engine breaks down in modules Search and (position) Evaluation as shown in the following diagram. If available, the determination of the move is initially delegated to an opening book. Only if the book does not provide a standard move Search is used.
Fig.: Engine, building block view, level 2
|Search||Determines the optimal move for a position under certain conditions.|
|Evaluation||Evaluates a position from an opponent’s perspective.|
Table: Modules of Engine subsystem