A piece plays across a critical square so that it is not interfered by another piece occupying this square.
See also: Critical move; Brasil theme.
Abdurahmanović, Fadil
Magyar Sakkélet, 1979
1.Ba7
Bxh6
2.Rd4
Se3#
1.Rd1
Rxh6
2.Bd4
Sd6#
Bakcsi, György
Die Schwalbe, 1967
1st Prize
1.h2
Rg1
2.h1=Q
Rf5
3.Qh8
Rgg5
4.Qxe5
Rxe5#