the difference in value between a Rook and a Bishop or a Knight.
To win the exchange, in this sense, means to capture a Rook and
to lose for it only a Bishop or a Knight.

Double Pawn


Two Pawns of the same player standing in one file are called a
double Pawn. Three Pawns in one file are called a triple Pawn.


Passed Pawn


A Pawn whose advance to the eighth rank is not blocked by an
opposing Pawn in the same file and who does not have to pass one
on an adjoining file is called a passed Pawn.


Isolated Pawn


A Pawn is called isolated if there are no Pawns of the same
player on the adjoining files.


Backward Pawn


A Pawn is called backward if he cannot advance far enough to be