3 | | | | | | | | | |---------------------------------------| 2 | ^P | ^P | ^P | | | ^P | ^P | ^P | |---------------------------------------| 1 | | | | | | | | | --------------------------------------- a b c d e f g h

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.

Following are a few examples: 

Supposing White, after (1) P-e4, P-e5, plays (2) P-d4.  Then Black is immediately threatened with the loss of his center-Pawn, which he cannot defend with P-d6 as after (3) Pxe5, Pxe5 White would exchange Queens and thereby deprive Black of the possibility of bringing his Rooks quickly into cooperation through castling.

(2) ..., Kt-c6 is out of question too; not on account of (3) P-d5, which merely helps Black in getting his Knight over to the King’s wing via e7 and allows him to maintain his center-Pawn, but on account of (3) Pxe5, Ktxe5; (4) Pf4, which secures the control of the center for White and does not leave Black a chance to advance his Queen’s Pawn to d5 with the view of depriving White of his center-Pawn too.

For these reasons Black has no choice but has to play (2) ..., Pxd4.  True enough, Black gives up his center-Pawn with this exchange, but White cannot prevent P-d5 in the long run, so that he also loses his center-Pawn and has no advantage over Black in that respect.  The following variations are typical for the line of play in cases of this kind.  White tries to hold back Black’s Queen’s Pawn as long as he can, but finally Black enforces the advance.