[ECO code A14]
(to) London Variation
Black's QBP to his third rank blocks QB3(c6) for his QKt. Similar to the London system (where, at the cost of rapid castling, his QB is outside rather than inside an equivalent pawn skeleton). B-Alt.
White Black White Black 1. P-QB4 P-K3 5. 0-0 0-0 2. Kt-KB3 P-Q4 6. P-Kt3 P-B3 3. P-KKt3 Kt-KB3 4. B-Kt2 B-K2
Example ends: Undo or Jump or Clear