Intermediate & Advanced Levels: Game analysis: Capablanca–Treybal, 1929: Space Advantage
Let's start with a raw definition: Space advantage is the availability of squares to post the pieces actively, compared to those available to the opponent, in a given sector of the board, or the board as a whole. By active piece we're talking about either threatening the opponent's material or taking control of critical squares inside his position.
The space advantage is largely defined by the pawn structures of both players, and is supported by the piece activity. This last is clear when we place a pair of White Rooks in a1 and b1, and a pair of Black pawns in a7 and b7: Although White has no Queen's side pawn structure, his piece activity grants him better control and mobility in it.
Now, the problem most have with understanding what exactly is space advantage and how to use it, comes from the fact the space advantage has meaning only when considered with the other elements on the board (material, time, piece activity), and that there isn't one single and unique form of space advantage. For example, the space advantage in the center of the board is different from the space advantage in a flank. In turn, the space advantage in a flank has different meanings when the center is closed, when it's not, when it's stabilized, when there's tension in it, when the opponent has space advantage in the other flank, and so on. It all depends, the same way having an extra pawn doesn't always decide the result. That is, the space advantage is just one element between all those that need to be considered when evaluating and playing a position, the same as the legs in a table.
However, the space advantage and its use can be outlined in general terms:
By principle, the attacker must concentrate his forces to overcome the defenders. The space advantage is closely linked to this principle and the sector where the attacker is operating, because having more squares to post the pieces gives higher mobility and flexibility to the attacking forces, in order to overcome the forces' dispositions available to the defender.
Essentially, every attack's ultimate goal works around achieving superiority of forces against a specific point in a given moment of the game. The space advantage may not guarantee this, but it certainly increases the possibility of its existence and creation.
The well known method to use this advantage is to tie down the defender's forces by the use of direct threats and pressure, particularly against weaknesses, and then to make use of the temporal increased mobility, of the attacking forces, to transfer them into another point and achieve the superiority there.
Sometimes, no superiority can be achieved immediately, and simultaneous and continued pressure and threats are necessary to force positional concessions from the defender, and to create a situation where the defender's forces can't mobilize between the different points fast enough.
The following game is a classic example of the creation and the exploitation of the space advantage. What was originally meant to be a Queen's side attack carried out under favorable conditions, evolved into a much more complex and deeper game, where Capablanca's strategy and positional game gave raise to strong tactics only in the last few moments of it.