Also Troitzky line. Endgame analysis by Alexey Troitsky of two knights versus a pawn found certain pawn positions that result in win, draw or loss. The resulting pawn positions on each file form what is known as the Troitsky line or Troitsky position.

Even though two knights cannot force checkmate (with the help of their king) against a lone king (with the exception of positions where white wins in 1 move), decreasing the material advantage and allowing the defending king to have a pawn can actually allow for a forced checkmate. The reason that checkmate can be forced is that the pawn gives the defender a piece to move and deprives him of a stalemate defense (Müller & Lamprecht 2001:19–20). Another reason is that the pawn can block its own king's path without necessarily moving (e.g. Kling & Horwitz position right).

The Troitsky line (or Troitsky position) is a key motif in chess endgame theory in the rare but theoretically interesting ending of two knights versus a pawn.