The Arabian mate
A rook and knight team up to trap a king in the corner. One of the oldest mating patterns there is.
Rook and knight in the corner
Black's king is in the corner. The knight on f6 guards h7 and g8. If the rook checks from h7, the knight protects it, so the king cannot take, and the rook itself covers g7. Every square is gone. The pattern is very old: it was already known in shatranj, the Arabic ancestor of chess.
Close the corner
Your turn
Checkmate in one move.
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Rook to h7 is mate. The knight protects the rook and covers g8, and the rook covers g7.
Bring the knight with check
Your turn
Mate in two. The knight joins the attack with check first.
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Knight to f6 check leaves only h8, since Black's own bishop blocks f8 and your rook covers the seventh rank. Then rook to h7 is the Arabian mate.
Why the seventh rank?
Question
Why is a rook on the seventh rank so useful for this mate?
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It can slide straight to h7, and it keeps the king off the seventh rank meanwhile
From the seventh rank the rook reaches h7 in one move and guards g7 the whole time.