The importance of studying endgames.

Some time ago a friend told me that learning rook endings is one of the most important things in chess. The reason for this is that rook endings are very common and if we put some energy in studying practical endgames we can get a lot in return. Here is an example of a game that I played in a correspondence tournament at Chessworld.com. After having been in trouble in the middlegame we reached a drawish endgame that I won because of a big mistake of my oponent.