The applications on this site all search a game tree to determine the value of the game, i.e. the number of tricks taken. This search can become very complex in single dummy solvers that simultaneously take into account all possible worlds, i.e. all possible distributions of the opponent's cards. This is for example what ScanSuit does One of the basic elements of this search, universally used in all game trees, is the Minimax algorithm, augmented; by a pruning procedure called Alpha-Beta. You can download below a didactic application showing how these algorithms work. AlphaBeta.exe