In every game, there will be some kind of fight for the centre. The centre is the heart of the chess board, where all of the action is happening. If you gain strong central control, you have more options of where to focus your attack later on in the game.
In the corner of the chess board, a knight has control of 2 squares. At the edge, it has 4 squares, but in the centre of the board, a knight has control of 8 squares. The potential of the knight is maximised therefore when placed in the centre. To support your central pawns, the knights are often used, because they are short ranged pieces, suitable for this purpose.
Please get your chess board out now, as I start with the notation.
King`s Indian Defence
To demonstrate this principle, I have annotated the 14th game of the World Championship Match between M. Botvinnik (white) and V. Smyslov (black), Moscow 1954:
1. d4 Nf6 2. c4 g6 3. g3 Bg7 4. Bg2 O-O 5. Nc3 d6 6. Nf3 Nbd7 7. O-O (figure 1)
In this position, white has a strong grip on the centre with the pawns on c4 and d4. Whites knights are well placed on c3 and f3, from where they support their own pawns, and control the central squares (d4, d5, e4, e5). If white can play the move e4 soon, then white`s big centre would be hard to break down. To circumvent this, black strikes back in the centre immediately, with 7…, e5 White continues 8. e4 c6 (figure 2).
The move c6 prepares d5, where black gains more space, and doesn`t become overpowered by whites big centre. If black didn`t play these moves, then the position would soon become cramped, and black`s pieces would be restricted.
9. Be3 Ng4 Trying to exchange blacks knight for white`s bishop on e3, because at the top level it is widely believed that bishops are slightly favourable to knights, in most positions. 10. Bg5 Qb6 11. h3 Botvinnik was now surprised by: exd4! (figure 3) When he had probably expected the knight to drop back with (11…, Nf6). If white takes black`s knight here, then black will take his. Materialistically this trade is fair, but positionally white is doing worse, because his centre has fallen apart.
This position has already become complicated, but white finds a good move here, which alleviates the threat of his knight being captured and at first it seems to win material… 12. Na4 It seems that since black has 2 pieces under attack, one of them will be lost. However due to tactical reasons, which Smyslov will have calculated beforehand, black can win back the temporarily lost piece. Qa6 13. hxg4 b5! (figure 4).
The white knight on a4 has no squares to go to, so instead of worrying about a piece that is lost anyway, white wins back a central pawn with 14. Nxd4 bxa4 15. Nxc6 This is a tactic, not a blunder…, Qxc3 (figure 5)
How does white win back the material? Notice that the white light squared bishop is on the same diagonal as the black queen and rook. With white`s next move, white skewers these pieces. 16. e5 The tactical justification. Qxc4 17. Bxa8 Now black is the ‘exchange’ down. In return for this material loss, black claims that he is positionally better, and this soon liquidates in the form of material gains as we shall see… Nxe5 18. Rc1 Qb4 19. a3 Qxb2 20. Qxa4 (figure 6)
Here black finds an excellent move 20…, Bb7! With the exchange of light squared bishops, the white king would suffer vulnerability on the light squares, which were previously guarded by the light squares bishop. From here onward, things complicate further, as the next sequence of moves brings about the exchange of: the black queen for both white bishops and his rook. 21. Rb1? (if white had played the simple 21. Bxb7, then the position would have been roughly equal. For example 21…, Qxb7 22. Rc3 h6) …, Nf3+ 22. Kh1 Bxa8! 23. Rxb2 Nxg5+ A discovered check – when the knight moves it unleashes the bishop. 24. Kh2 Nf3+ 25. Kh3 Bxb2 (figure 7)
After the exchanges have been made, black is clearly in an advantageous position. The three pieces are plenty enough for the queen, when in a few moves time they are fully coordinating. 26. Qxa7 Be4 27. a4 Kg7 28. Rd1 Be5 29. Qe7 Rc8! (figure 8) Now the rook is ready to join in the attack. Notice that black`s king is safe on g7, because the white queen can`t threaten the king by herself, and black`s dark squared bishop guards against any checks on the dark squared diagonal.
30. a5 Rc2 31. Kg2 Blacks light squared bishop does a fine job of controlling white`s passed a-pawn`s queening square – a8. …, Nd4+ discovered check. 32. Kf1 Bf3 33. Rb1 Nc6 White resigned. (figure 9)
In this game, the control of the centre proved to be so important, especially in the middlegame. With 11…, exd4 black proved that white`s centre was not as solid as it seemed. After 14. Nxd4 White recaptures a lost pawn in the centre. When black plays 17…, Nxe5 white`s centre has collapsed altogether and the only plus in his position is that he has a queen.