Connected rook and knight pawns

Connected rook and knight pawns are a friendly pair on the a-file and b-file, or on the g-file and h-file. Files are the vertical lines labeled a through h. Pawns on the a-file and h-file are rook pawns, while those on the b-file and g-file are knight pawns, because those pieces begin behind them.

Connected means that the pawns occupy neighboring files and may come to support each other diagonally. It does not mean that a rook or knight is nearby. It also does not by itself mean that the pawns are passed. If no enemy pawn can stop either one by capturing, they form a special case of connected passed pawns.

Endgame manuals, which study the phase with few pieces left, treat this pair separately because the board edge changes the geometry. A king can approach from only one side, the squares where the pawns can become new pieces lie near a corner, and different defensive resources arise, especially in queen endings. A practical rule that works for central connected pawns may therefore fail for this pair.

To evaluate them, determine whether they are passed, how close they are to the last rank, which king supports them, which promotion squares the opponent controls, meaning the squares where the pawns could become new pieces, and whose turn it is.