MultiPV

A principal variation is the sequence that a chess engine, an analysis program, currently considers best for both sides. In normal analysis it commonly displays only one. MultiPV asks the engine to maintain and rank several alternatives from the starting position, each with its own principal variation and evaluation.

With MultiPV set to three, for example, the interface may show the first, second, and third candidate moves. This helps compare plans, find a practical alternative close to the top choice, or see whether only one move preserves the position. The ranking is not permanent: it can change as the search reaches greater depth, discovers a tactic, or refines its estimate.

Requesting more lines spreads time and computing capacity across more starting moves. With the same resources, analysis may progress more slowly or reach less depth than a search focused on one choice. The displayed scores are not independent probabilities either; they are evaluations produced within the same search process.

MultiPV also does not mean that the engine lists every reasonable idea. It shows the requested number of candidates according to its current ranking. Result quality still depends on factors such as move ordering and available time. Its name refers to principal variations, but it should not be confused with the specific algorithm called principal variation search.