(9) ...            Ktxb3
(10) Pxc7         Qxc7

+---------------------------------------+
8 | #R |    | #B |    | #K | #B |    | #R |
|---------------------------------------|
7 |    |    | #Q |    |    | #P | #P | #P |
|---------------------------------------|
6 | #P |    |    |    |    | #Kt|    |    |
|---------------------------------------|
5 |    | #P |    |    | #P |    | ^Kt|    |
|---------------------------------------|
4 |    |    |    |    |    |    |    |    |
|---------------------------------------|
3 |    | #Kt|    | ^P |    |    |    |    |
|---------------------------------------|
2 | ^P | ^P | ^P |    |    | ^P | ^P | ^P |
|---------------------------------------|
1 | ^R | ^Kt| ^B | ^Q | ^K |    |    | ^R |
+---------------------------------------+
a    b    c    d    e    f    g    h

Diagram 65.

Black could regain his Pawn by Q-d5; (11) Pa2xb3, Qxg2; (12) Q-f3, Qxf3; (13) Ktxf3, B-b7; (14) K-e2, B-d6 and Bxc7; but in doing so he would give up his advantage in development, which, as the further course of the game proves, is much more valuable.

(11) Pa2xb3        B-b7
(12) o-o           P-h6!

If Black proceeded to develop his pieces indiscriminately, his advantage would soon vanish.  White needs only two moves—­R-e1 and Kt-e4—­to paralyze the effect of Black’s powerful Queen’s Bishop and to regain control of the center where at present Black has the upper hand on account of his center-Pawn.

(13) Kt-f3 B-d6 (14) R-e1 o-o (15) Ktb1-d2 Ra8-d8 (16) P-c3

White does not risk Kt-e4 as Black, after Ktxe4; (17) Pxe4, can uncover the Rook by B-b4 attacking White’s Queen and Rook at the same time.  White’s only defense would be (18) B-d2 or Kt-d2, but he would pin himself badly in either case and Black would obtain an overwhelming attack by P-f5, which enables his King’s Rook to join the fray.

With P-c3 White protects himself against B-b4 and now actually threatens to interrupt the diagonal of Black’s Queen’s Bishop.  Black will naturally try to prevent this and the first move which presents itself for the purpose is P-e4, opening a line for the Bishop d6 and the Queen at the same time.  At first sight the move does not seem playable as on e4 the Pawn is three times attacked and only twice defended; but White cannot withdraw both the Knight d2 and the Pawn d3 from the Queen’s file on account of the threat Bxh2+ winning the Queen for Rook and Bishop.  Black can, therefore, safely advance the Pawn.

+---------------------------------------+
8 |    |    |    | #R |    | #R | #K |    |
|---------------------------------------|
7 |    | #B | #Q |    |    | #P | #P |    |
|---------------------------------------|
6 | #P |    |    | #B |    | #Kt|    | #P |
|---------------------------------------|
5 |    | #P |    |    | #P |    |    |    |
|---------------------------------------|
4 |    |    |    |    |    |    |    |    |