A superior pawn center may be tactically vulnerable before it is entrenched.
Andras Adorjan White
Boris Spassky Black
Toluca 1982
English Defense A40
1 c4 b6 2 d4 ♗b7 3 ♘c3 e6 4 e4 ♗b4 5 ♗d3
White would have a nice edge if his center stands, e.g. 5...♘f6? 6 ♕c2 ♘c6 7 ♘f3.
5...f5!
So that 6 exf5 ♗xg2 loses. Note that 6 f3 fxe4 7 fxe4 drops a pawn to 7...♗xc3+ 8 bxc3 ♗xe4 9 ♗xe4 ♕h4+.
6 ♕h5+ g6 7 ♕e2 ♘f6
The sacrifice 8 e5? ♗xg2 9 exf6 ♕xf6 is unsound. See below.
8 f3 ♘c6!
This attacks the d4-pawn. After 9 ♗e3 Black has a choice, including 9...fxe4 10 fxe4 e5 (so that 11 d5 ♘d4 favors him).
9 e5? ♘xd4! 10 ♕f2
Now 10...♗c5 threatens 11...♘xf3+.
Question 106: How would White defend?
10...♘h5!
This is what he missed (11 ♕xd4 ♗c5! and the queen is trapped).
White would be losing after 11 ♗e3 ♘c6 12 f4 g5 (or even 12...d6 13 exd6 ♘f6! and ...♘g4).
Question 107: Yes, but what about 11...♗c5 ?
11 ♕xd4 ♗c5 12 ♕xc5 bxc5
Black won after 13 ♗e3 ♕h4+ 14 g3 (14 ♗f2 ♕g5) ♘xg3 15 ♗f2 f4 16 ♗e4 0-0-0.
Ma Yu White
Albert Bokros Black
Groningen 1999
1 d4 b6 2 c4 ♗b7 3 ♘c3 e6 4 e4 ♗b4 5 ♗d3 f5 6 ♕e2 ♘f6 7 e5? ♗xg2 8 exf6 ♕xf6 9 f3 ♗xh1 10 ♕f2 (intending ♘e2, ♗d2, 0-0-0 and ♖xh1) ♘c6 11 ♘e2 e5! 12 ♔f1 ♗xc3 13 ♘xc3 e4 14 ♘0d5 ♕xd4 15 ♕xd4 ♘xd4 16 ♘xc7+ ♔f7 17 ♘xa8 exd3 18 ♘c7 ♖c8 19 ♗f4 ♗xf3 20 ♔f2 ♗h5 21 h4 ♖xc7 22 ♗xc7 d2 23 ♗e5 ♘c6 White resigns.