Ukrainian Mikhail Zinar's chess studies are among my favorite positions.
Here is a particularly interesting study - full of knight promotions...
Mate in 20
[fen]8/2p1p1p1/PpP1P1P1/1K2P1P1/P7/4p3/pp2P1p1/kn2R3 w - - 0 1[/fen]
More studies and analysis with downloads (PGN) here:
https://glarean-magazin.ch/2021/01/12/problem-schach-der-studien-komponist-mikhail-zinar-the-master-of-the-knights-chess/
Here is a particularly interesting study - full of knight promotions...
Mate in 20
[fen]8/2p1p1p1/PpP1P1P1/1K2P1P1/P7/4p3/pp2P1p1/kn2R3 w - - 0 1[/fen]
More studies and analysis with downloads (PGN) here:
https://glarean-magazin.ch/2021/01/12/problem-schach-der-studien-komponist-mikhail-zinar-the-master-of-the-knights-chess/