Find positions with a white rook on the seventh rank — Nimzowitsch's 'pig on the seventh.' Rakes the opponent's pawn base and harasses the king.
A rook on the seventh rank is one of chess's most fearsome pieces — Aron Nimzowitsch coined the phrase "a pig on the seventh" because of its appetite for the opponent's pawns. The rook attacks the pawn base from the side, restricts the opposing king to the back rank, and often coordinates with another rook (the "blind pigs") for decisive material gains. Reaching the seventh is an almost-automatic strategic goal in any open or semi-open position.