Weak Squares
Weak squares are those that cannot be protected by pawns and hence the opponent can use them as strong points for his pieces. In this game Black weakens his d5 and then the b5 and c4 squares, of which Fischer skillfully takes advantage.
Bobby Fischer-Herbert Seidman
New York 1956
1.Nf3 Nf6 2.g3 c5 3.Bg2 Nc6 4.O-O e5 5.d3 d5 6.e4 Be7 7.Nbd2 O-O 8.Re1 dxe4
This pawn exchange is usually good for White because of the resulting weak d5 square. Better is 8...d4.
9.dxe4 Qc7 10.c3 b6 11.Qe2 a5
In order to play ...Ba6, but now Black has two more weaknesses at b5 and c4.
12.a4
Fixing the weakness.
12...Ba6 13.Nc4 b5
A bad move. Now the a- and c-pawns will be targets. Black's position becomes quite lifeless.
14.axb5 Bxb5 15.Bf1
In order to free the Queen from the defense of the Knight.
15...Rad8 16.Qc2 Ng4
Black's pieces are not engaged in coordinated, concerted action, but are merely attacking ``here and there.''
17.h3 Nf6 18.Nfd2
White on the other hand correctly coordinates his pieces to take advantage of Black's weaknesses on the queenside.
18...Rfe8 19.Nb3 Qc8
19...Bxc4 would only have temporarily saved a pawn. Black's position would have remained very bad.
20.Kh2 Qe6 21.Nbxa5
White has won a pawn and the outcome is not in doubt.
21...Nxa5 22.Nxa5 Bxf1 23.Rxf1 c4 24.Qe2 Rd3 25.Ra4 Red8 26.Nxc4 h6 27.Re1 Bc5 28.Kg2 g5 29.Nd2 Qd7 30.Ra5 Bb6 31.Ra6 Qb7 32.Ra1 Qd7 33.Nc4 Bxf2 34.Qxf2 Nh5 35.Nxe5 Qe6 36.Nxd3 Rxd3 37.Re3 Rd1 38.Qf3 Qb3 39.Qxh5 1-0