Mutual capture of two enemy pieces, which exchange their active (capturing) and passive (captured) role between phases.
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
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#