Chess endgames are often complex and require careful analysis to be successful. One important aspect of endgame strategy is identifying the key squares on the board. Key squares are those squares that, when controlled by one player, can make it difficult or impossible for the other player to make progress. In our case (pawn endgames), the player needs to identify squares to ensure the pawn promotion by controlling them.
The pawn endgames are somewhat specific, as it is always necessary to distinguish between rook pawns and other pawns. Let’s go through both situations.
A rook pawn is a pawn on one of the rook files – a or h – and aiming to reach a corner square. Corner squares are often overlooked in the endgame, but they can be crucial in certain situations. For example, in a king and pawn endgame, controlling the corner squares with the king can make it difficult for the opponent to make progress, as they cannot attack the king from both sides.
Two key squares are typically associated with an advanced rook pawn, namely the squares adjacent to the promotion square on the same file. For instance, a white a-pawn’s key squares would be b7 and b8, while those of a white h-pawn would be g7 and g8.
Green dots mark the key squares – if the white king gets to one of them, Black cannot stop the pawn from promoting. On the other hand, if the black king reaches the red crosses, the game is a draw, as it either blocks the pawn or avoids the white king to reach the key squares.
In contrast to rook pawns, pawns occupying other positions on the board have a higher number of key squares. Specifically, if a pawn is located on the second, third, or fourth rank, then there are three key squares available to it. These squares consist of the one two squares ahead of the pawn, along with the squares to its left and right.
We will pay a special attention to the pawn on the fifth and sixth rank later, as it is closely related to another important concept – the opposition.
Knight pawn exception
The rule concerning key squares has an exception that applies when a knight pawn (b-file or g-file) is situated on its sixth rank, the defending king occupies a corner square, and the defending player is the one who is currently making a move.
White to move – white wins. Black to move – a draw (stalemate).
Grandmaster game example
The game position involving Svetozar Gligorić and Bobby Fischer serves as an example of the importance of key squares in chess. If we take Black’s perspective, a move such as 57. … ♚b8 would prevent the white king from occupying a key square, leading to a draw in the game. This illustrates the strategic significance of controlling key squares on the board.
By understanding and utilizing these key squares, players can increase their chances of success in the endgame.