Knight with 11. B to R 4, he retires the Bishop, so as to avoid a double pawn. Now he has to prevent White's Knight from moving to B 5, attacking the Queen, but in doing so he weakens his King's position for the purpose of castling on the King's side. The student should bear in mind that these pawns are strongest in their original position.

13.B to B 2...

The Bishop is better placed now at B 2. At R 4 it was, owing to the changed position, less useful. At its new post it strengthens the centre.

...13.P to Q 4

Black anticipates White's possible P to Q 4 by himself advancing.

14.Castles14.P takes P
15.P takes P15.Kt to Q sq.

Black now executes the manœuvre which was suggested at his ninth move. But it is not so good at this stage. The position is now as shown in Fig. 7.

16.Q R to Q sq....

It is always good to occupy an open file with a Rook.