Grimshaw (chess)

A. G. Corrias,
Good Companion, 1917
abcdefgh
8
8
77
66
55
44
33
22
11
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White to play and mate in two

A Grimshaw is a device found in chess problems in which two pieces (usually a rook and bishop) arriving on a particular square mutually interfere with each other. It is named after the 19th-century problem composer Walter Grimshaw. The Grimshaw is one of the most common devices found in directmates.