This article further examines how to formulate a middle game plan according to where one possesses an advantage in space.
Here's a position from an informal game, where Black has just played 8...Re8.
To focus on the pawn structure, visualize the board having been cleared of everything else:
To determine which player has more space, we will examine the number of ranks each player has available behind his pawns.
Therefore, White's meaningful space advantage consists of one extra square along the d-file, which isn't much. One consequence of this is that the d3-square is available to a White piece, whereas the corresponding d6-square is occupied by a Black pawn. Also, White may be able to effectively occupy the d5-square, whereas if Black were to liquidate at the d4-square, the following pawn structure would result.
Here White's space advantage on the d-file, in terms of squares each player can occupy on his side of the pawn, is 5 to 2. This outweighs Black's 4 to 3 space advantage on the e-file; moreover, a Black piece on the e5-square might be dislodged by the advance of White's f-pawn to the fourth rank. Therefore, the position would be favorable for White.
Here again, is the position with the pieces restored:
So what should White's plan be? White decided to use his extra space to try to position his pieces in preparation for the eventual pawn exchange at e5. The queen's bishop was deployed to b2, where it would bear down on the e5-square after White played dxe5 followed by Nd5. Placing the bishop at g5 would have been weaker because exchanging at f6 would merely ease Black's cramp. Alternatively, putting the bishop at e3 would block the e1-rook from protecting the e-pawn, thus impeding Nd5 because of Black's possible reply ...Nxe4.
Because the exchange of pawns at e5 produces symmetrical pawn structure, it was imperative that White refrain from that exchange - that is, retain the tension - until he felt his pieces were better able than Black's to exploit the opening of the position. If Black were permitted to play an early ...Bg4, the pin on the knight might have increased Black's pressure on White's d-pawn enough to compel him to exchange pawns or advance the d-pawn, either of which would have disrupted White's plans. To avoid this pin, White had advanced the h-pawn.
The game continued 9. a3 h6 10. b4 a6 11. Bb2 b5 12. Bb3 Qc8 13. dxe5 dxe5 14. Nd5, with strong pressure. Perhaps Black's best reply was 14...Bd8, but White could then have doubled on the d-file or played 15. c4 followed by cxb5 and putting a rook opposite Black's backward c-pawn.
Here's another position, also from an informal game. Black has just played 14...a6.
Clearing the board except for pawns:
Going file by file:
White should endeavor to utilize his space advantage along the d- and e-files by also advancing the f-pawn to create pawn tension. Then, as in the first game, White could try to configure his pieces optimally before opening things up. The next diagram depicts a possible attacking configuration of the White pieces.
If Black were to respond to the pressure against his e-pawn by playing either ...e5 or ...exf5, that would concede control of the d5-square and invite White's knight to invade there. But if Black instead leaves the e6-pawn where it is, he would need to prevent fxe6 followed by Rf7. This could be done by keeping a rook at f8 (so long as this rook was doubly protected), but then this piece would not be participating in Black's queenside offensive. Another attacking possibility for White is to advance the f-pawn to the sixth rank in order to weaken Black's kingside pawn front.
In Black's favor is the space advantage along the c-file, which Black might amplify by advancing the b-pawn to attack White's knight. Then White's c-pawn would be pressured along the file and Black might also play ...Qa5 to attack the then undefended a-pawn.
In the game continuation, White did initiate an attack on the kingside but was unable to generate sustained threats because his f-pawn was left at f2. As a result, Black's queenside attack quickly brought about a winning position.
I hope the reader has benefited from these two brief excursions into the role of pawns in the middlegame.