Black’s intention of exerting pressure on the KP is now difficult of execution, because his pieces are very cramped and hinder one another in a restricted area.  The KB in particular cannot be brought into action without great difficulty, for instance by:  R-K1, B-KB1, P-KKt3, and B-Kt2.  It is therefore advisable for White to develop his QB at Kt2 instead of at Kt5, in order not to give Black a chance of exchanging his troublesome Bishop. (In a game Bernstein-Emanuel Lasker, Moscow, 1914, there happened 9.  BxKt, PxB; 10.  B-Kt5, P-KR3; 11.  B-R4, Kt-R2; 12.  BxB, QxB with a good game for Black.)

The defence has a totally different trend, if Black gives up his own KP, but captures the White KP at once.  I have already pointed out that White would not mind his KP being taken, in view of the attack on the open King’s file.  Let us now consider in which way this attack can be planned.  There are two essentially different lines, according to whether Black interpolates P-QR3 or not.

After 3.  B-Kt5, Kt-B3; 4.  Castles, KtxP; 5.  R-K1, Black gets out of it comfortably by playing Kt-Q3, B-K2 and Castles, and White cannot permanently prevent Black’s game from being freed by the advance of the QP.  P-Q4 for White on the fifth move is therefore stronger.  Black cannot very well exchange the pawns, leaving the King’s file quite exposed, and must submit to White playing PxP, maintaining the pawn at K5 and preventing Black’s P-Q4 for some time to come.

The opening might continue in this way:  5.  P-Q4, B-K2; 6.  Q-K2, Kt-Q3; 7.  BxKt, KtPxB (to make room for the Kt); 8.  PxP, Kt-Kt2 (Diagram 25).

---------------------------------------
8 | #R |    | #B | #Q | #K |    |    | #R |
|---------------------------------------|
7 | #P | #Kt| #P | #P | #B | #P | #P | #P |
|---------------------------------------|
6 |    |    | #P |    |    |    |    |    |
|---------------------------------------|
5 |    |    |    |    | ^P |    |    |    |
|---------------------------------------|
4 |    |    |    |    |    |    |    |    |
|---------------------------------------|
3 |    |    |    |    |    | ^Kt|    |    |
|---------------------------------------|
2 | ^P | ^P | ^P |    | ^Q | ^P | ^P | ^P |
|---------------------------------------|
1 | ^R | ^Kt| ^B |    |    | ^R | ^K |    |
---------------------------------------
A    B    C    D    E    F    G    H

Diag. 25

The whole of the manoeuvres now centre round Black’s endeavours to force his P-Q4, and White’s attempt to prevent it.  Black ultimately gains his point, as will be seen, but at the expense of such disadvantages in the pawn position that it is questionable whether the whole variation (called the Rio de Janeiro Defence) is playable.