Rook and pawn versus rook endgame

The rook and pawn versus rook endgame is of fundamental importance to chess endgames (Keres 1973:100), (de la Villa 2008:123–25), (Emms 2008:16), (Burgess 2009:94), (Nunn 2009:106) and has been widely studied (Nunn 1999:6), (Minev 2004:58). Precise play is usually required in these positions. With optimal play, some complicated wins require sixty moves to either checkmate, win the defending rook, or successfully promote the pawn (Speelman, Tisdall & Wade 1993:7). In some cases, thirty-five moves are required to advance the pawn once (Thompson 1986).

The play of this type of ending revolves around whether or not the pawn can be promoted, or if the defending rook must be sacrificed to prevent promotion. If the pawn promotes, that side will have an overwhelming material advantage. If the pawn is about to promote, the defending side may give up his rook for the pawn, resulting in an easily won endgame for the superior side (a basic checkmate). In a few cases, the superior side gives up his rook in order to promote the pawn, resulting in a won queen versus rook position (see Pawnless chess endgame#Queen versus rook).

A general rule of thumb (with exceptions) is: if the king on the side without the pawn can reach the queening square of the pawn, the game is a draw; otherwise it is a win for the opponent (except with a rook pawn, i.e. a- or h-file) (Fine & Benko 2003:294ff). The side with the pawn can cut off the opposing king or strive for the Lucena position, which is a win. The defender can aim for the Philidor position (which is a draw) or try to set up one of the other defensive techniques that draw (Mednis 1987:93). A rook and two pawns usually win against a rook, but there are plenty of exceptions.

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