If Black is ready to admit that Kt-d5 is a disagreeable threat he will either exchange the Knight for his Bishop b4 or he will play Kt-e7 in order to take White’s Knight should he go to d5.  Ordinarily Black plays first Bxc3 and then Kt-e7.  The reason is that this maneuver enables Black to get his Queen’s Knight over to the King’s wing while White’s Bishop b5 is rather out of action, so that Black has a good chance to enter the battle on the King’s wing with one piece more than White.  Of course, White can get his Bishop into play again by placing him on c4.  But he has to spend a move in doing so, which does not add to the completion of the development.

In the position of Diagram 46 Black would not take any steps to prevent Kt-d5 unless a threat is involved in this move which cannot be counteracted by the most natural continuation, which is the development of the Bishop c8.  Indeed, there seems to be no reason why Black should not answer (1) B-g5 with B-g4 and (2) Kt-d5 with Kt-d4; for the Knight f6, who after Kt-d5 is attacked twice, is defended twice, and there is no possibility for White to attack the Knight again.  On the other hand, the attack on the Bishop b4 is balanced by the attack on the Bishop b5, and if White were to withdraw his Bishop to c4 Black could withdraw his to c5.

However, in the position resulting after these moves (Diagram 47) White gets the upper hand because he is one move ahead in the attack on the opposing King’s Knight.  The danger of the concentration of two pieces on this Knight lies in the fact that Black is obliged to retake with the g-Pawn in case White exchanges on f6 and that thereby the squares f6 and h6 lose their natural protection.

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

Diagram 47.

Thus weak points are created of which White may find an opportunity to make use in a manner similar to the one illustrated by the discussion of Diagrams 26 and 29.  On the other hand, Black gains an open file for his Rooks as soon as the g-Pawn is out of the way, and the exchange on f6 should therefore not be made until preparations for the occupation of the resulting weak spots are completed.  The following variations will throw some light on this rather complex problem.