Rook + Pawn v.s. Rook
There are three things worth noting in this position:
1. The passed pawn must be supported by the King, but in order to promote, it will have to leave the King later.
2. Keep the defending King away from the passed pawn.
3. The Rook is best when placed behind the passed pawn for both sides.
Here is the tricky part of the move:
