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a b c d e f g h
8 a8 b8 c8 d8 e8 f8 g8 h8 8
7 a7 b7 c7 k d7 e7 f7 g7 b h7 p 7
6 a6 b6 r c6 p d6 e6 f6 g6 h6 6
5 a5 p b5 c5 P d5 e5 f5 g5 p h5 5
4 a4 b4 c4 d4 e4 p f4 g4 h4 p 4
3 a3 b3 c3 d3 e3 f3 g3 h3 P 3
2 a2 b2 c2 K d2 e2 f2 g2 P h2 2
1 a1 b1 c1 d1 e1 f1 R g1 h1 1
a b c d e f g h
A free Rook is on b6. cxb6+ loses the valuable Passed Pawn asset. Luckily, Rf7+, a zwischenzug kicking the King back to rank 8 allows Pawn to take loss-free.

A zwischenzug (German for "intermediate move") is an in-between move played instead of the expected move. The move produces an urgent threat, one that is quickly addressed, and the first player plays as normal. The tactic leaves the first player with a better position or material advantage.