Tarrasch Rule - Exceptions

Exceptions

Purdy

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

White to move draws by repeatedly checking from the first rank.

There are exceptions to the Tarrasch rule. Here are some.

• Yuri Averbakh said that the Tarrasch rule is usually correct when only the rooks are battling over the pawn, but when the pawn is blocked by the opposing king, the rook of the same color as the pawn is normally better protecting the pawn from the side (Emms 2008:87).
• In the rook and pawn versus rook endgame, if the pawn is not beyond its fourth rank, the best place for the defending rook is in front of the pawn (Howell 1997:38–40), (Dvoretsky 2006:150ff).
• On a similar note, Cecil Purdy said that a rook is best behind its passed pawn if it is on the fifth rank or higher, or can reach those ranks. If the pawn is held up before the fifth rank, the rook is better in front of the pawn. Often the rook is best protecting the pawn from the side if it is on the fifth rank or higher (Purdy 2003:114).
• In the ending of a rook and pawn versus a rook, if the defending king is cut off from the pawn's file, then the best defence is with the rook on its first rank (Howell 1997:37). See the frontal defense.
• In the ending of a rook and pawn versus a rook, where the pawn is a knight pawn (b- or g-file), the defending king is in front of the pawn, but the defender cannot get his rook to the third rank for the drawing Philidor position, the defending rook draws on its first rank but loses if it is attacking the pawn from behind (Mednis 1982:16), (Fine & Benko 2003:295).
• In the ending of a rook and two isolated pawns versus a rook, it is generally better for the stronger side to protect the pawns from the side (Mednis 1982:29).
• If the pawn is a rook pawn it is often better for the rook to attack it from the side, especially in a rook and pawn versus rook position (Nunn 2009:120). (See the Vančura position.)
• If a rook is in front of its passed pawn, it is often best for the defending rook to attack from the side. In fact, it is sometimes best to switch the defending rook from behind the pawn to the side (Nunn 2010:38–44).
• In the ending of a rook versus a pawn or pawns, the rook is best placed on its first rank (Fine & Benko 2003:275–92), (Mednis 1998:47).
• When a rook is battling against pawns, if the pawns are not connected, it is often best for the rook to hold the pawns up along a rank (Nunn 2010:22).