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 which 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 which cannot be blocked or captured by enemy pawns in its advance to promotion is a passed pawn. In the diagram, White has a protected passed pawn on c5 and Black has an outside passed pawn on h5. 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 that is 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. The diagrammed 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 ,