Outside Passed Pawn
An outside passed pawn is a pawn that is a passed pawn and is also on the “outside” of the board. Typically it is a rook pawn or Knight pawn. This distinguishes it from a “central passed pawn” which refers to a Queen pawn ("d’ pawn) or King pawn ("e’ pawn). A bishop pawn ("c’ or "f’ pawn) isn’t really an outside passed pawn, but it’s not that central either.
Note that an outside passed pawn does not always win. The types of pawn structures that are often stronger than an outside passed pawn are:
- Supported passed pawn
- Connected passed pawns (two passed pawns)
In the absence of any compensating pawn structures (i.e. if your opponent does not have a supported passed pawn or connected passed pawns), then the outside passed pawn should win. In a King-and-Pawn endgame, there are a few ways to win with an outside passed pawn:
- Sacrifice the outside passed pawn to divert the enemy King. The way this works is you push your passed pawn about half way, then you just leave it so that the enemy King has to go walk over to eat it, meanwhile your King has invaded enemy territory and will eat all the enemy pawns. Then you queen one of your other pawns.
- King marches the passed pawn to queen: If your King can support the passed pawn from behind, with the enemy King trying to block the pawn from in front of it, you can gradually force the enemy King backward with your King through zugzwang. Then you can slowly push your pawn to the 6th or 7th rank, where you have a choice: (a) leave the pawn there and run with your King to eat the base of the other enemy pawn chain, or (b) intentionally half-stalemate the enemy King against the end of the board with your pawn, thereby forcing your opponent to move some other pawn (taking care not to actually stalemate them if they can then offer all their pawns to be taken!).
Outside passed pawns are also important in other endgames with pieces.
- Rook endings: There are lots of chess games where one player has a single passed pawn on the Queenside, while both Kings and other pawns are on the Kingside. The game greatly depends on whether your rook is behind the outside passed pawn (usually best), beside the pawn (second best), or in front of its own passed pawn (still often winnable).
- Bishop with Outside Passed Pawn: an outside passed pawn is a winning advantage in Bishop endings (although perhaps not if Opposite Color Bishop Endings). The Bishop cannot itself force the pawn forward as it cannot control squares of both color, and will need the King’s help often.
- Knight with Outside Passed Pawn: an outside passed pawn is an advantage in a Knight ending, but paradoxically, sometimes the Knight will have an easier win if it has a Central Passed Pawn.
Related Chess Tactics
Read more about these related chess strategies: