BISHOP'S OPENING - Classical Var.
The Petroff Gambit
Black developed his queen to K2(e7) (sometimes called the queen's
natural defensive square). White advances his Queen's Pawn to the centre
to threaten Black's K4Pawn.
White Black
1. P-K4 P-K4
2. B-B4 B-B4
3. Kt-KB3 P-Q3
4. P-B3 Q-K2
5. P-Q4