This method compares partial order evaluations in the leaves of a game tree, but backs up only boolean values through the tree. We also define LE-POB, a closely related algorithm that uses standard alphabeta search with values from a suitably chosen linear extension of the partially ordered set. We discuss the use of partial order move evaluation for move ordering and for pruning dominated moves during search. We show an application of the method to capturing races called semeai in Go. Liberty and eye counts of blocks in a semeai are used to construct an exact partial order evaluation.
Experiments show the resulting speedups compared to standard alphabeta search.