It is a well known phenomenon that the same amateur who can conduct the middle game quite creditably, is usually perfectly helpless in the end game. One of the principal requisites of good chess is the ability to treat both the middle and end game equally well.
Aron NimzowitschThe main Objective of any operation in an open file is the eventual Occupation of the seventh or eighth Rank.
Aron NimzowitschThe knight of QB3 is under obligation, the moment the enemy gives him the chance, of undertaking an invasion of the center by Kn-Q5.
Aron NimzowitschStrategically important points should be overprotected. If the pieces are so engaged, they get their regard in the fact that they will then find themselves well posted in every respect.
Aron NimzowitschHow is it to be explained that something inside me revolts against the playing of obvious moves? Perhaps we may perceive the underlying reason in the fact that I derive satisfaction from seeking to reveal the concealed meaning of a position by means of maneuvering play and therefore I do not wish to see this satisfaction curtailed by a banal, more or less fortuitous decision. Naturally, this phenomenon is played out beneath the threshold of consciousness. The waking consciousness will, of course, in each individual case, give preference to the more rapid means of deciding the game.
Aron Nimzowitsch