We often hear the terms 'positional' and 'tactical' used as opposites. But this is as wrong as to consider a painting's composition unrelated to its subject. Just as there is no such thing as 'artistic' art, so there is no such thing as 'positional' chess.
Samuel ReshevskyThe knight is renowned for, among other things, its suitability as a blockader ... Because its strength lies in short-range operations it is not uncomfortable standing in a single spot for long periods, as the Bishop is.
Samuel ReshevskyWhat is a weak pawn? A pawn that is exposed to attack and also difficult to defend is a weak pawn. There are several varieties: isolated, doubled, too advanced, retarded.
Samuel Reshevsky