The 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 NimzowitschChess strategy as such today is still in its diapers, despite Tarrasch's statement 'We live today in a beautiful time of progress in all fields'. Not even the slightest attempt has been made to explore and formulate the laws of chess strategy.
Aron Nimzowitsch