In the initial position, a black king's flight is blocked by the black piece A. In the final position, the same flight square is blocked by another black piece B.
See also: Changed blocks.
Garai, Toma
Thema Danicum, 1976
Prize
a) 1.Qg1
Sg3
2.Rf1
Se4
3.Ra1
Sc3#
b) 1.Qh8
Sf2
2.Bg7
Sd3
3.Ba1
Sc1#
Caillaud, Michel
Shakhmatna Misl, 1982
1st Prize
1.Bd8
a5
2.Bb6
axb6
3.c1=B
b7
4.Bg5
b8=S
5.Be7
Sd7#
1.Qb3
a5
2.Qb6
axb6
3.c1=Q
b7
4.Qc4
b8=S
5.Qf7
Sd7#
1.Rb8
a5
2.Rb6
axb6
3.c1=R
b7
4.Rc8
b8=S
5.Re8
Sd7#
Loustau, Jean-Marc
Ideal-Mate Review, 1986
Prize
1.Sc7
Kf1
2.Kd5
Kg2
3.Bd6
Kg3
4.c5
Kf4
5.Sc6+
Kxe3
6.e5
Kd3
7.Se6
e4#
Nastran, Janez
Slovenian Championship, 1993
1st Place
a) 1.Qf2
Qxe6+
2.Sxe6
Rxf2#
b) 1.Qd7
Qxe5+
2.Rxe5
Bxd7#
c) 1.Qd5
Qxf4+
2.Bxf4
Rxd5#
Trillon, Jean-Michel
feenschach, TT-25, 1972
2nd Prize
1.Rg8+
Kd7
2.Rb7+
Kxc6
3.Rbg7+
Kb5
4.Rb8+
Ka4
5.Rb2
Sc3#
Moen, Kabe
The Problemist Supplement, 2019
a) 1.Re5
Bh7
2.Sc5
Bd3
3.Sde6
Be4#
b) 1.Bd6
Rf1
2.Sc6
Rf7
3.Sed4
Rf5#
Földeák, Árpád
Revista de Sah, 1963
5th HM
1.h3
b8=R
2.h2
Rxb2
3.h1=R+
Rh2
4.Sb2
Rh3
5.Rb1
Ra3#
Maslar, Zdravko
feenschach, 1988
1.Qa1
c4
2.Qh1
c5
3.g1=R
c6
4.Ra1
c7
5.Ra7
c8=Q#