Gaviota tablebases

Gaviota is a family of tablebases, precomputed databases for endings with few pieces. Miguel A. Ballicora originally developed them for his Gaviota engine, and their probing code can be integrated into other software. The usual set covers three-, four-, and five-piece positions, counting both kings.

Their characteristic value is DTM, which means distance to mate. In a won position it gives the distance to checkmate under play that minimizes that distance; in a lost position it reflects resistance that delays mate. Within the covered material, the result is exact rather than an approximate engine evaluation.

DTM and the fifty-move rule answer different questions. A mathematically shortest route to mate may still take too long without a capture or pawn move, so a rules-based game could be drawn. A Gaviota result should therefore be distinguished from a result that explicitly incorporates the current fifty-move count.

Compared with Syzygy, Gaviota covers fewer pieces but provides direct distance-to-mate data. Nalimov also uses DTM and reaches six pieces, but it has a different format, compression system, and integration history.