Mutual capture of two enemy pieces, which exchange their active (capturing) and passive (captured) role between phases.
See also: Cycle of captures.
Caillaud, Michel
Liga Problemista, Mat Plus, 2009
1st Place
a) 1.Ke3
Bd3
2.Ba6
c3
3.Bxd3
Sd5#
b) 1.Bf5
Bc8
2.Ke3
Bxf5
3.gxf5
Sxf5#
Abdurahmanović, Fadil
Chumakov, Gennadij
4th Azemmour TT, Belgrade, 2016
1st-3rd Prize
1.Rxa4
Sxc1
2.Rxa5
Sd3
3.Ra6
Se5
4.Rg6
Sf7#
1.Sxa2
Rxa3
2.Sxc3
Ra1
3.Se4
Rf1
4.Sg5
Rf6#
Abdurahmanović, Fadil
Zajic, Helmut
Schach-Aktiv, 2005
2nd Prize
1.b3
Rxg5
2.Qa3+
Bxa3
3.Kxa3
Rxa5#
1.Qxc3+
Bb2
2.Qxb2+
Kxb2
3.Bb5
Ra1#
Kolesnik, Mikola
7th FIDE World Cup, 2019
1st Prize
1...Rxh1
2.Bxg6
Rxb1
3.Bxe4+
Sxe4
4.Ba3
Sc3#
1...Bxh5
2.Sxg5
Bd1
3.Sxe4
Rxe4
4.Ka3
Rxa4#
1...Sxf3
2.Rxh4
Sxd2
3.Rxe4
Bxe4
4.a3
Bxb1#
Gurov, Valery
6th FIDE World Cup, 2018
3rd Prize
1.Qd5
Sd2
2.Qxd2+
Bxd2
3.Rxf4
Bxf4#
1.Rd4
Bd2
2.Rxd2
Sxd2
3.Qxf3+
Sxf3#