Rook Endgame Essentials - Part 1

The third world chess champion Jose Raul Capablanca once famously said : "In order to improve your game, you must study the endgame before anything else; for whereas the endings can be studied and mastered by themselves, the middlegame and the opening must be studied in relation to the endgame." 

Rook endings appear much more often than any other type of an endgame. For this article, I have prepared the first part of the rook endgame essentials. The article contains : Philidor and Lucena positions, as well as several examples of the long side, short side principle.