A thorough knowledge of the elements takes us more than half the road to mastership
Aron NimzowitschIt 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 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 Nimzowitsch