2. PAWN ENDINGS
There is nothing more logical than to commence the study of the endgame with pawn endings. The reason for this is that pawn endgames are not only the basis of all other endgames. They may be the simplest in form, but not always in content! As a “fighting unit” the pawn is quite a plodder. It moves slowly and quite predictably. As a consequence, its tactical possibilities are seriously limited. That is why pawn endgames are ideal for exploring the almost inexhaustible range of king moves as well as the amazing geometry of the chess board (“curvature” of space!). Despite its apparent simplicity, pawn endgames may turn out quite complicated and reveal some exceptionally beautiful subtleties. Their complexity is compounded by the fact that the assessment must be definitive and concrete. In contrast to other stages of the game or other endgames, the evaluation of a pawn endgame is clear. It cannot end with a statement such as e.g. “White has a slight advantage”, or “Black stands clearly better” or “with a huge advantage”. We must always go till the end and pronounce the true verdict. The position is a draw or the position is a win!
Basic rules and strategic ideas in pawn endings
In order to fully comprehend pawn endgames one must first assimilate the basic rules and strategic ideas: the significance of the critical squares (key squares), the rule of the “square”, opposition and corresponding squares, triangulation, the gaining of a tempo, penetration, defence by a stalemate, restriction of activity, the rule of the “common square” and also become familiar with the specific “curvature” of the chess-board. All these elements will be examined one by one, depending on the type of the position and the basic didactic principles inherent to it. For the sake of simplicity and universality, we shall always refer to the stronger side as “White”. Likewise the fourth rank, the fifth rank, the sixth rank etc. will mean the fourth rank of White, the fifth rank of White etc.
2.1.King and One Pawn versus King
As king and one pawn generally cannot create mating threats or otherwise force a direct win, the crucial question is whether the pawn can promote into the queen. There are many complicated positions with the enemy king in front of the pawn. Yet they all observe the “rule of the critical squares (key squares)”.
What are “critical squares” (or “key squares”)?
For all pawns – excepting those on a- and h-files and also those on the sixth rank, the critical squares are the three squares symmetrically positioned two rows in front of the pawn. For the pawns on the sixth rank the critical squares are the three symmetrical squares on the eighth rank. As well as the three symmetrically placed squares immediately before the pawn, for the pawns on the rook’s files there are only two critical squares on the adjacent file on the seventh and eighth ranks. These three exceptionally important but essentially different situations are shown in diagram 7. However, the basic rule of the theory of critical squares always holds. White wins by promoting his pawn provided he can gain control of one of the critical squares.