7. Q-Q2 P-QR3
not P-QB4 at once, because of Kt-Kt5.
8. Kt-Q1 P-QB4 9. P-QB3
II
7. P-B4 Castles
8. Kt-B3 P-QB4
9. B-Q3 P-B4
10. Castles Kt-QB3
and so on.
In both cases White has an easy development, whilst Black has no convenient square for his Queen’s Bishop.
To avoid this drawback Rubinstein has evolved the following variation, in which provision is made from the first for the freedom of action of the Queen’s Bishop:
3. Kt-QB3 Kt-KB3 4. B-Kt5 PxP
to open the diagonal for the Bishop at QKt2, e.g.: