There is no hard and fast answer. It depends on what both you and your opponent do.
For example, White, ideally, would love to have an uninterrupted pair of pawns on d4 and e4. Total pipe dream, of course, as even in the case of hypermodern openings, your goal is to break up their center.
For example, put White pawns on e4 and d4. They control 4 key squares, namely c5, d5, e5, and f5. If you had to advance the d-pawn to d5, now suddenly they only control c6, e6, and f5, all light squares, and the dark squares become weakened.
So chipping away at the center causes weaknesses. This is known as a Hypermodern approach.
The other approach, and the approach that is recommended to all beginners and players under 1800, is a more classical approach. Instead of letting the opponent occupy the center and try to chip away at it, which could cause you to suffocate, instead, you fight for the center from the get-go.
Let's say White opens with 1.e4. Black does not want White to be able to own two pawns on e4 and d4, controlling the center. Well, he's already played e4, so let's fight for d4. 1...e5 is the best move here. If White tries to advance d4 right away, Black can take it, and if White recaptures, Black can gain time attacking the Queen with moves like ...Nc6, developing a Knight and making White move the Queen again. So 1...e5 is a deterrant to White playing d4.
However, let's say White plays 1.d4. Well, now, Black should fight for control of e4, since White already got the d-pawn out two squares, we need to prevent him from getting the second pawn out two squares. So we play 1...d5, so that if White plays 2.e4, we just take it and win a pawn.
You can't go into the game pre-meditating what you will attack.
Take what I play against 1.e4 as an example. After 1.e4 e6 2.d4 d5, Black immediately attacks e4 and makes White do something about it. Black can't, however, pre-meditate that he will attack a certain central square. If White takes with 3.exd5, then when Black takes back, trying to attack d4, especially if White plays c3 at some point, is useless, and will do nothing but weaken your structure. If, however, White advances the pawn with 3.e5, now that all pressure is off of d5 and White has committed, Black can play an early 3...c5 and attack d4 because that target is fixed. White can ill-afford to take on c5 as it will weaken e5 severely. So White waits for Black to trade on d4, which he should hold off until he has to do it, keeping tension, and then after the pawn trade, that pawn is backwards and is White's weak spot in the position.
So again, there is no hard and fast rule, and you have to understand the position and situation of the squares and pawns in the center, factoring in stability, fixed or fluid pawns, how the pieces are arranged, etc.
Hi there,
In every chess book they advise to fight for the center. Ok. But for which square ? d4 or e4 ? Why e4 and not d4 ? And why d4 and not e4 ? Why not for e5 ... or d5 ? How does good players think to make such a decision ?
Let's me know :-)