H#2: A black line-piece makes a critical move along the line on B1. Another black piece moves onto that line on B2, making an interference of the piece moving on B1 and unguarding mating square or line.
This is the theme of the 26th SABRA Composing Tourney (Batumi, 2023).
See also: Cheney-Loyd theme.
Witztum, Menachem
Polish Chess Fedetation, 2023
a) 1.Bd4
Ba3
2.Se5
Sf6#
b) 1.Rc6
Be3
2.Sd6
Be6#
FEN: 4b3/3B1n2/5b2/3k1P2/K5Nr/3P4/8/2B5
Witztum, Menachem
Polish Chess Fedetation, 2023
1.Be6
Rh1
2.f5
Rh4#
1.Bh8
Bc5
2.f6
Bxd6#
FEN: 3n4/3p1p2/3p2pK/3pb1P1/4Pkb1/2p2rp1/5Bp1/4R3