This game between Howard Staunton and Elijah Williams is very illustrative of the importance of the different kind of oppositions in chess. If you haven’t read the lesson about the opposition it is probably better to read this first.
As you will see Staunton has lost the game, but you have to know that the virtual opposition was something nobody was aware of in 1851. Without these kind of guidelines it is very difficult to play this kind of endgame the right way.
But with all the lessons you have learned in this series the endgame is rather easy to play. The next lesson is about the Trébuchet.