Chess How to Control Squares

This is a position that arises out of a very well known Gambit called the Smith Mora. A Gambit is giving up a pawn for positional gain. Here white is threatening to push e5. If e5 is pushed it would be a disaster for Black. After the ...dxe5, Nxe5, Nxe5 and Bxe5 and that bishop on e5 is a monster. It is tempting for Black to push the pawn to e5. It stops white from pushing, it forces the bishop to move, thereby gaining a tempo, and protects (at least temporarily) the pawn on d6 by blocking it from the bishop. But the problem with that move involves squares, and this is a good opportunity to talk about the importance of squares.

If Black is only worried about holding onto his extra pawn, he can get into some very ugly trouble. If he gives into the temptation to give up the d5 square by pushing the e-pawn, or alows white to push his black pawn, his extra pawn won't mean diddly squat. He will be under constant pressure which will eventually result in a piece loss, or a checkmate. Additionally, if he worries too much about doubling that extra pawn he allows too much of an attack to develop for White. (In the above diagram the pawns are doubled on the e file. Doubled pawns are not always weak, but players learn early the general principle that they are weak, which is normally true. But not here.) He is still up the extra pawn, and White's attack is over. Black has time, because he has shut down White's play, to develop the rest of his pieces and get castled. Alternatively, if White had access to that d5 square, he could post a knight there that would be a monster. The d6 pawn would also just be a backward pawn, making it hard to defend and likely to fall anyway. The Bishop could simply move out of the way of the one move threa, and choose between the diagonal it is on, or the g1-a7 diagonal where it could support other possible annoying posts for the knight.

 The Smith-Mora Gambit is a response to the Sicilian opening. 1. e4 c5 (c5 is the Sicilian) Then White plays 2. d4 cxd4 (still not a gambit as white can recapture with his Queen.) 3. White plays 3. c3?? Now it's a gambit. Some players try to avoid the gambit. You can push the pawn, and force white to give up the two center pawns, but you are also giving up the extra pawn, and helping him to develop his light squared bishop when he recaptures with it. You can ignore it, and let him capture with the c-pawn, but that gives up one of the best things about the Sicilian, the center pawns black often gets. You can do numerous other moves, for example you can try to guard with e5. But this system of capturing the pawn and then planning to place the knight on e5 to block the pawn push, and recapture with the pawn leaving doubled pawns, may be the best way to play it. As long as you remember the importance of squares, in this case d5, you should be able to remember what to play. Also remember to keep White's pieces out with prophylactic moves like a6, keeping his knight and bishop out, and d6 and e6, stopping his bishop from tricky sacrifices and the knights from inroads.