One must attempt to increase whatever weakness there may be in the opponent’s position; or, if there is none, one or more must be created. - José Raúl Capablanca

you must study the endgame before everything else.

I am always reminded of the case of a noted American journalist, an excellent fellow, well educated, and, at the time I have in mind, chess champion of the state in which he resided. My friend devoted a great deal of time and energy to the study of the openings. Whenever I passed through his city he always came to the station for me and put me up at his house. We would have frequent con- versations during which he would ask me about this or that variation; to his great surprise I would almost always answer, "I don't know it" Then he would say: "What will you do when somebody plays it against you?" And I would reply, "Ninety percent of the book variations have no great value, because either they contain mistakes or they are based on fallacious assumptions; just forget about the openings and spend all that time on the endings. In the long run you will get much better results that way."

In order to improve your game, you must study the endgame before everything else, for whereas the endings can be studied and mastered by themselves, the middle game and the opening must be studied in relation to the endgame.