Then, it can check whether that is true by searching the remaining nodes with a null window (also known as a scout window when alpha and beta are equal), which is faster than searching with the regular alpha–beta window. In other words, it supposes the first node is in the principal variation. It produces more cutoffs than alpha–beta by assuming that the first explored node is the best. In practice, the move ordering is often determined by previous shallower searches. NegaScout works best when there is a good move ordering. It dominates alpha–beta pruning in the sense that it will never examine a node that can be pruned by alpha–beta however, it relies on accurate node ordering to capitalize on this advantage.

Like alpha–beta pruning, NegaScout is a directional search algorithm for computing the minimax value of a node in a tree. Principal variation search (sometimes equated with the practically identical NegaScout) is a negamax algorithm that can be faster than alpha–beta pruning. An enhancement of Alpha–Beta game tree search

Betago algorithm