Rook against knight: split them is lesson 3 of 6 in Endgame 9: Queen against rook, rook against minor piece, an endgame course suited to players rated around 2200 (advanced players). A knight far from its king can be cut off or trapped, and then the rook wins. It has 6 interactive exercises: 6 calculated lines from real positions. You play every move on a board and get feedback straight away. The lesson is free.
What you practise
White to move and win. (3 positions)
Black to move and win. (3 positions)
Worked examples
White to move and win. 1.Re4+ Kf5 2.Rxd4. Only Re4+ wins: the knight is cut off from its king. This is a won endgame (checked with endgame tables). After Kc5 the win would be gone.
Black to move and win. 1...Rf1+ 2.Kd2 Rxa1. Only Rf1+ wins: the knight is cut off from its king. This is a won endgame (checked with endgame tables). After Kd5 the win would be gone.
More in Endgame 9: Queen against rook, rook against minor piece