DIAGRAM 44.

The advance of the d-Pawn, besides the possibility of opening the
d-file for the Rooks, has another very important purpose. It
invites, and often compels the opponent to take the Pawn with his
e-Pawn thereby losing control of "the center." What is meant by
center in King's Pawn openings will be understood from the
analysis of the Diagram 44 in which only the Pawn skeleton of a
King's Pawn game is given and in which it is assumed that Black
has exchanged the Pawn e5 for the Pawn d4. This Pawn formation
offers an advantage to White because the Pawn e4, White's center-
Pawn, controls the two squares d5 and f5 while the two
corresponding squares in White's camp, that is d4 and f4, are not
in the hands of Black and could be occupied by White men. It is
evident that it must be advantageous to have pieces placed in the
center of the board as there they have naturally more mobility
than towards the edge of the board where part of their radius of
action is cut off. A Knight, for instance, placed on d4 will
possibly have an opportunity later on to go to f5 from where he
helps an attack on g7. The square f4 may be useful for the Queen
in an attempt to reach the King's wing speedily, thus
accumulating on that part of the board superior forces. These and
other advantages connected with the control of the center will be
more readily understood after the discussion of the middle game
maneuvers of which the center squares form the basis. It is
necessary, however, to touch upon this matter at this time, as in
many openings the player is confronted after the very first moves
with questions in which the maintenance of the center-Pawn is the
point at issue.