i like this one, it's pretty interesting
Mate in 4, really hard

makes no sense
It's simple. White to play and mate in 4 moves. Only one line of play achieves this.
I don't understand the first rook move as well as the capture with bishop, but I do understand the rest.

I don't understand the first rook move as well as the capture with bishop, but I do understand the rest.
1 Ra1 threatens an unstopable mate after Ra5 and Rd5. So, the Rook must be captured.
2 Rh4 prepares a pin of the g pawn, so the Knight could go to f3 after white moves his Bishop.
I don't understand the first rook move as well as the capture with bishop, but I do understand the rest.
1 Ra1 threatens an unstopable mate after Ra5 and Rd5. So, the Rook must be captured.
2 Rh4 prepares a pin of the g pawn, so the Knight could go to f3 after white moves his Bishop.
Nice.
This is a wonderful puzzle. Only one line is given in the solution here, see if you can figure out the rest.
Mate in 4
Opificius (Oswald von Krobshofer)
Schach Express 1948
Dedicated to Emil Ramin