Endgames are one of the most important parts of chess. If you know and play endgame well, the middle game will always be much easier to play because you understand what you want in the endgames. Rock and pawn endgames are one of key endgame because so many games are decided with that type of endgame.
GM Yasser Seirawan is one of the grandmasters in the history. He had a deep understanding in the endgame, and that’s way it´s reason to stop and listen when the opportunity rise to listen to him in lecture and rock and pawn endgame.
This video is from his lecture in the Chess Club in St. Louis, but that chess club has many brilliants videos, highly recommended.