Pawn structure The
pawn structure, the configuration of pawns on the chessboard, determines the strategic flavor of a game. While other pieces can usually be moved to more favorable positions if they are temporarily badly placed, a poorly positioned pawn often cannot be so relocated. In addition, being the most numerous piece, the pawn structure restricts and directs the piece movements of each side. Because pawns capture diagonally and can be blocked from advancing, opposing pawns can become locked in diagonal of two or more pawns of each color, where each player controls squares of one color. In the diagram, Black and White have locked their d- and e-pawns. Here, White has a long-term advantage. White will have an easier time than Black in finding good squares for their pieces, particularly with an eye to the . Black, in contrast, suffers from a on c8, which is prevented by the black pawns from finding a good square or helping out on the kingside. On the other hand, White's central pawns are somewhat and vulnerable to attack. Black can undermine the white pawn chain with an immediate ...c5 and perhaps a later ...f6.
Isolated pawn Pawns on adjacent files can support each other in attack and defense. A pawn that has no friendly pawns in adjacent files is an
isolated pawn. The square in front of an isolated pawn may become an enduring weakness. Any piece placed directly in front not only blocks the advance of that pawn but also cannot be driven away by other pawns. In the diagram, Black has an isolated pawn on d5. If all the pieces except the kings and pawns were removed, the weakness of that pawn might prove fatal to Black in the
endgame. In the
middlegame, however, Black has slightly more freedom of movement than White and may be able to trade off the isolated pawn before an endgame ensues.
Passed pawn A pawn that cannot be blocked or captured by enemy pawns in its path to promotion is a
passed pawn. Because endgames are often won by the player who can promote a pawn first, having a passed pawn in an endgame can be decisive – especially a protected passed pawn (a passed pawn protected by a pawn). In this vein, a pawn
majority, a greater number of pawns belonging to one player on one side of the chessboard, is strategically important because it can often be converted into a passed pawn. In the diagram, White has a
protected passed pawn on c5 and Black has an
outside passed pawn on h5. This position might appear roughly equal, because each side has a king and three pawns, and the positions of the kings are about equal. In truth, White wins this endgame on the strength of the protected passed pawn, regardless which player moves first. The black king cannot be on both sides of the board at once – to defend the isolated h-pawn and to stop White's c-pawn from advancing to promotion. Thus White can capture the h-pawn and then win the game.
Doubled pawn After a capture with a pawn, a player may end up with two pawns on the same , called
doubled pawns. Doubled pawns are substantially weaker than pawns that are side by side, because they cannot defend each other or both be defended by adjacent pawns, and the front pawn blocks the advance of the back one. In the diagram, the doubled c-pawns are a strategic disadvantage for Black. There are situations where doubled pawns confer some advantage; for example, the guarding of consecutive squares in a file by the pawns prevents an invasion by the opponent's pieces, and the side with doubled pawns typically has additional open files for rooks. Pawns that are both doubled and isolated are typically a tangible weakness. A single piece or pawn in front of doubled isolated pawns blocks both of them, and cannot be easily dislodged. It is rare for a player to have three pawns in a file, i.e.
tripled pawns.
Wrong rook pawn In chess endgames with a bishop, a may be the
wrong rook pawn, depending on the square-color of the bishop. This causes some positions to be
draws that would otherwise be wins. ==History==